- The Agile software development lifecycle is dominated by the iterative process. Each iteration results in the next piece of the software development puzzle - working software and supporting elements, such as documentation, available for use by customers - until the final product is complete.
- Continuous Integration in Agile Software Development Traditional software development methods don’t dictate how frequently to integrate source code. The more programmers share code, the more problematic it is. Agile teams may use Continuous Integration. Facebook; Twitter; Email; LinkedIn.
Software development |
---|
Core activities |
Paradigms and models |
Methodologies and frameworks |
Supporting disciplines |
Practices |
Tools |
Standards and Bodies of Knowledge |
Glossaries |
Agile software development comprises various approaches to software development under which requirements and solutions evolve through the collaborative effort of self-organizing and cross-functional teams and their customer(s)/end user(s).[1] It advocates adaptive planning, evolutionary development, early delivery, and continual improvement, and it encourages rapid and flexible response to change.[2][further explanation needed]
The term agile (sometimes written Agile)[3] was popularized, in this context, by the Manifesto for Agile Software Development.[4] The values and principles espoused in this manifesto were derived from and underpin a broad range of software development frameworks, including Scrum and Kanban.[5][6]
While there is much anecdotal evidence that adopting agile practices and values improves the agility of software professionals, teams and organizations, some empirical studies have disputed that evidence.[7][8]
One of the trending model in software development life-cycle i guess!:) Agile model is one of the Incremental model which results in small incremental releases where the each release building on previous functionality. Few features of Agile mode. Agile Development is one of the big buzzwords of the software development industry which is a different way of managing software development projects. Rather than a specific software development method, it is an umbrella term for a set of methods and practices based on the values and principles expressed in the Agile Manifesto.
- 2The Manifesto for Agile Software Development
- 3Overview
- 4Philosophy
- 5Agile software development methods
- 6Experience and adoption
- 6.1Measuring agility
- 6.2Common agile software development pitfalls
- 7Agile management
History[edit]
Iterative and incremental development methods can be traced back as early as 1957,[9] with evolutionary project management[10][11] and adaptive software development[12] emerging in the early 1970s[13].
During the 1990s, a number of lightweight software development methods evolved in reaction to the prevailing heavyweight methods that critics described as overly regulated, planned, and micro-managed. These included: rapid application development (RAD), from 1991;[14][15] the unified process (UP) and dynamic systems development method (DSDM), both from 1994; Scrum, from 1995; Crystal Clear and extreme programming (XP), both from 1996; and feature-driven development, from 1997. Although these all originated before the publication of the Agile Manifesto, they are now collectively referred to as agile software development methods.[6] At the same time, similar changes were underway in manufacturing[16] and aerospace.[17]
In 2001, these seventeen software developers met at a resort in Snowbird, Utah to discuss these lightweight development methods: Kent Beck, Ward Cunningham, Dave Thomas, Jeff Sutherland, Ken Schwaber, Jim Highsmith, Alistair Cockburn, Robert C. Martin, Mike Beedle, Arie van Bennekum, Martin Fowler, James Grenning, Andrew Hunt, Ron Jeffries, Jon Kern, Brian Marick, and Steve Mellor. Together they published the Manifesto for Agile Software Development.[4]
In 2005, a group headed by Cockburn and Highsmith wrote an addendum of project management principles, the PM Declaration of Interdependence,[18] to guide software project management according to agile software development methods.
In 2009, a group working with Martin wrote an extension of software development principles, the Software Craftsmanship Manifesto, to guide agile software development according to professional conduct and mastery.
In 2011, the Agile Alliance created the Guide to Agile Practices (renamed the Agile Glossary in 2016),[19] an evolving open-source compendium of the working definitions of agile practices, terms, and elements, along with interpretations and experience guidelines from the worldwide community of agile practitioners.
The Manifesto for Agile Software Development[edit]
Agile software development values[edit]
Based on their combined experience of developing software and helping others do that, the seventeen signatories to the manifesto proclaimed that they value:[4]
- Individuals and Interactions over processes and tools
- Working Software over comprehensive documentation
- Customer Collaboration over contract negotiation
- Responding to Change over following a plan
That is to say, the items on the left are valued more than the items on the right.
As Scott Ambler elucidated:[20]
- Tools and processes are important, but it is more important to have competent people working together effectively.
- Good documentation is useful in helping people to understand how the software is built and how to use it, but the main point of development is to create software, not documentation.
- A contract is important but is no substitute for working closely with customers to discover what they need.
- A project plan is important, but it must not be too rigid to accommodate changes in technology or the environment, stakeholders' priorities, and people's understanding of the problem and its solution.
Free fifa 2008 game download for pc. Some of the authors formed the Agile Alliance, a non-profit organization that promotes software development according to the manifesto's values and principles. Introducing the manifesto on behalf of the Agile Alliance, Jim Highsmith said,
The Agile movement is not anti-methodology, in fact many of us want to restore credibility to the word methodology. We want to restore a balance. We embrace modeling, but not in order to file some diagram in a dusty corporate repository. We embrace documentation, but not hundreds of pages of never-maintained and rarely-used tomes. We plan, but recognize the limits of planning in a turbulent environment. Those who would brand proponents of XP or SCRUM or any of the other Agile Methodologies as 'hackers' are ignorant of both the methodologies and the original definition of the term hacker.
— Jim Highsmith, History: The Agile Manifesto[21]
Agile software development principles[edit]
The Manifesto for Agile Software Development is based on twelve principles:[22]
- Customer satisfaction by early and continuous delivery of valuable software.
- Welcome changing requirements, even in late development.
- Deliver working software frequently (weeks rather than months)
- Close, daily cooperation between business people and developers
- Projects are built around motivated individuals, who should be trusted
- Face-to-face conversation is the best form of communication (co-location)
- Working software is the primary measure of progress
- Sustainable development, able to maintain a constant pace
- Continuous attention to technical excellence and good design
- Simplicity—the art of maximizing the amount of work not done—is essential
- Best architectures, requirements, and designs emerge from self-organizing teams
- Regularly, the team reflects on how to become more effective, and adjusts accordingly
Overview[edit]
Pair programming, an agile development technique used by XP.
Iterative, incremental and evolutionary[edit]
Most agile development methods break product development work into small increments that minimize the amount of up-front planning and design. Iterations, or sprints, are short time frames (timeboxes) that typically last from one to four weeks. Each iteration involves a cross-functional team working in all functions: planning, analysis, design, coding, unit testing, and acceptance testing. At the end of the iteration a working product is demonstrated to stakeholders. This minimizes overall risk and allows the product to adapt to changes quickly.[23] An iteration might not add enough functionality to warrant a market release, but the goal is to have an available release (with minimal bugs) at the end of each iteration.[24] Multiple iterations might be required to release a product or new features. Working software is the primary measure of progress.[22]
Efficient and face-to-face communication[edit]
The principle of co-location is that co-workers on the same team should be situated together to better establish the identity as a team and to improve communication.[25] This enables face-to-face interaction, ideally in front of a whiteboard, that reduces the cycle time typically taken when questions and answers are mediated through phone, persistent chat, wiki, or email.[26]
No matter which development method is followed, every team should include a customer representative ('Product Owner' in Scrum). This person is agreed by stakeholders to act on their behalf and makes a personal commitment to being available for developers to answer questions throughout the iteration. At the end of each iteration, stakeholders and the customer representative review progress and re-evaluate priorities with a view to optimizing the return on investment (ROI) and ensuring alignment with customer needs and company goals.
In agile software development, an information radiator is a (normally large) physical display located prominently near the development team, where passers-by can see it. It presents an up-to-date summary of the product development status.[27][28] A build light indicator may also be used to inform a team about the current status of their product development.
Very short feedback loop and adaptation cycle[edit]
A common characteristic in agile software development is the daily stand-up (also known as the daily scrum). In a brief session, team members report to each other what they did the previous day toward their team's iteration goal, what they intend to do today toward the goal, and any roadblocks or impediments they can see to the goal.[29]
Quality focus[edit]
Specific tools and techniques, such as continuous integration, automated unit testing, pair programming, test-driven development, design patterns, behavior-driven development, domain-driven design, code refactoring and other techniques are often used to improve quality and enhance product development agility.[30] This is predicated on designing and building quality in from the beginning and being able to demonstrate software for customers at any point, or at least at the end of every iteration.[31]
Philosophy[edit]
Compared to traditional software engineering, agile software development mainly targets complex systems and product development with dynamic, non-deterministic and non-linear characteristics. Accurate estimates, stable plans, and predictions are often hard to get in early stages, and confidence in them is likely to be low. Agile practitioners will seek to reduce the leap-of-faith that is needed before any evidence of value can be obtained.[32] Requirements and design are held to be emergent. Big up-front specifications would probably cause a lot of waste in such cases, i.e., are not economically sound. These basic arguments and previous industry experiences, learned from years of successes and failures, have helped shape agile development's favor of adaptive, iterative and evolutionary development.[33]
Adaptive vs. predictive[edit]
Development methods exist on a continuum from adaptive to predictive.[34] Agile software development methods lie on the adaptive side of this continuum. One key of adaptive development methods is a rolling wave approach to schedule planning, which identifies milestones but leaves flexibility in the path to reach them, and also allows for the milestones themselves to change.[35]
Adaptive methods focus on adapting quickly to changing realities. When the needs of a project change, an adaptive team changes as well. An adaptive team has difficulty describing exactly what will happen in the future. The further away a date is, the more vague an adaptive method is about what will happen on that date. An adaptive team cannot report exactly what tasks they will do next week, but only which features they plan for next month. When asked about a release six months from now, an adaptive team might be able to report only the mission statement for the release, or a statement of expected value vs. cost.
Predictive methods, in contrast, focus on analysing and planning the future in detail and cater for known risks. In the extremes, a predictive team can report exactly what features and tasks are planned for the entire length of the development process. Predictive methods rely on effective early phase analysis and if this goes very wrong, the project may have difficulty changing direction. Predictive teams often institute a change control board to ensure they consider only the most valuable changes.
Risk analysis can be used to choose between adaptive (agile or value-driven) and predictive (plan-driven) methods.[36]Barry Boehm and Richard Turner suggest that each side of the continuum has its own home ground, as follows:[37]
Value-driven methods | Plan-driven methods | Formal methods |
---|---|---|
Low criticality | High criticality | Extreme criticality |
Senior developers | Junior developers(?) | Senior developers |
Requirements change often | Requirements do not change often | Limited requirements, limited features see Wirth's law[clarification needed] |
Small number of developers | Large number of developers | Requirements that can be modeled |
Culture that responds to change | Culture that demands order | Extreme quality |
Agile vs. waterfall[edit]
One of the differences between agile software development methods and waterfall is the approach to quality and testing. In the waterfall model, there is always a separate testing phase after a build phase; however, in agile software development testing is completed in the same iteration as programming.
Another difference is that traditional 'waterfall' software development moves a project through various Software Development Lifecycle (SDLC) phases. One phase is completed in its entirety before moving on to the next phase.
Because testing is done in every iteration—which develops a small piece of the software—users can frequently use those new pieces of software and validate the value. After the users know the real value of the updated piece of software, they can make better decisions about the software's future. Having a value retrospective and software re-planning session in each iteration—Scrum typically has iterations of just two weeks—helps the team continuously adapt its plans so as to maximize the value it delivers. This follows a pattern similar to the PDCA cycle, as the work is planned, done, checked (in the review and retrospective), and any changes agreed are acted upon.
This iterative approach supports a product rather than a project mindset. This provides greater flexibility throughout the development process; whereas on projects the requirements are defined and locked down from the very beginning, making it difficult to change them later. Iterative product development allows the software to evolve in response to changes in business environment or market requirements.[38]
Because of the short iteration style of agile software development, it also has strong connections with the lean startup concept.
Code vs. documentation[edit]
In a letter to IEEE Computer, Steven Rakitin expressed cynicism about agile software development, calling it 'yet another attempt to undermine the discipline of software engineering' and translating 'working software over comprehensive documentation' as 'we want to spend all our time coding. Remember, real programmers don't write documentation.'[39]
This is disputed by proponents of agile software development, who state that developers should write documentation if that is the best way to achieve the relevant goals, but that there are often better ways to achieve those goals than writing static documentation.[40]Scott Ambler states that documentation should be 'just barely good enough' (JBGE),[41] that too much or comprehensive documentation would usually cause waste, and developers rarely trust detailed documentation because it's usually out of sync with code,[40] while too little documentation may also cause problems for maintenance, communication, learning and knowledge sharing. Alistair Cockburn wrote of the Crystal Clear method:
Crystal considers development a series of co-operative games, and intends that the documentation is enough to help the next win at the next game. The work products for Crystal include use cases, risk list, iteration plan, core domain models, and design notes to inform on choices..however there are no templates for these documents and descriptions are necessarily vague, but the objective is clear, just enough documentation for the next game. I always tend to characterize this to my team as: what would you want to know if you joined the team tomorrow.
— Alistair Cockburn.[42]
Agile software development methods[edit]
Software development life-cycle support[43]
Agile software development methods support a broad range of the software development life cycle.[43] Some focus on the practices (e.g., XP, pragmatic programming, agile modeling), while some focus on managing the flow of work (e.g., Scrum, Kanban). Some support activities for requirements specification and development (e.g., FDD), while some seek to cover the full development life cycle (e.g., DSDM, RUP).
Notable agile software development frameworks include:
Framework | Main contributor(s) |
---|---|
Adaptive software development (ASD) | Jim Highsmith, Sam Bayer |
Agile modeling | Scott Ambler, Robert Cecil Martin |
Agile unified process (AUP) | Scott Ambler |
Disciplined agile delivery | Scott Ambler |
Dynamic systems development method (DSDM) | |
Extreme programming (XP) | Kent Beck, Robert Cecil Martin |
Feature-driven development (FDD) | Jeff De Luca |
Lean software development | Mary Poppendieck, Tom Poppendieck |
Lean startup | Eric Ries |
Kanban | Taiichi Ohno |
Rapid application development (RAD) | James Martin |
Scrum | Ken Schwaber, Jeff Sutherland |
Scrumban |
Agile software development practices[edit]
Agile software development is supported by a number of concrete practices, covering areas like requirements, design, modeling, coding, testing, planning, risk management, process, quality, etc. Some notable agile software development practices include:[44]
Practice | Main contributor(s) |
---|---|
Acceptance test-driven development (ATDD) | |
Agile modeling | |
Agile testing | |
Backlogs (Product and Sprint) | Ken Schwaber |
Behavior-driven development (BDD) | Dan North, Liz Keogh |
Continuous integration (CI) | Grady Booch |
Cross-functional team | |
Daily Stand-up / Daily Scrum | James O Coplien |
Domain-driven design (DDD) | Eric Evans |
Iterative and incremental development (IID) | |
Low-code development platforms | |
Pair programming | Kent Beck |
Planning poker | James Grenning, Mike Cohn |
Refactoring | Martin Fowler |
Retrospective | |
Scrum events (sprint planning, sprint review and retrospective) | |
Specification by example | |
Story-driven modeling | Albert Zündorf |
Test-driven development (TDD) | Kent Beck |
Timeboxing | |
User story | Alistair Cockburn |
Velocity tracking |
Method tailoring[edit]
In the literature, different terms refer to the notion of method adaptation, including 'method tailoring', 'method fragment adaptation' and 'situational method engineering'. Method tailoring is defined as:
A process or capability in which human agents determine a system development approach for a specific project situation through responsive changes in, and dynamic interplays between contexts, intentions, and method fragments.
— Mehmet Nafiz Aydin et al., An Agile Information Systems Development Method in use[45]
Situation-appropriateness should be considered as a distinguishing characteristic between agile methods and more plan-driven software development methods, with agile methods allowing product development teams to adapt working practices according to the needs of individual products.[46][45] Potentially, most agile methods could be suitable for method tailoring,[43] such as DSDM tailored in a CMM context.[47] and XP tailored with the Rule Description Practices (RDP) technique.[48][49] Not all agile proponents agree, however, with Schwaber noting 'that is how we got into trouble in the first place, thinking that the problem was not having a perfect methodology. Efforts [should] center on the changes [needed] in the enterprise'.[50] Bas Vodde reinforced this viewpoint, suggesting that unlike traditional, large methodologies that require you to pick and choose elements, Scrum provides the basics on top of which you add additional elements to localise and contextualise its use.[51] Practitioners seldom use system development methods, or agile methods specifically, by the book, often choosing to omit or tailor some of the practices of a method in order to create an in-house method.[52]
In practice, methods can be tailored using various tools. Generic process modeling languages such as Unified Modeling Language can be used to tailor software development methods. However, dedicated tools for method engineering such as the Essence Theory of Software Engineering of SEMAT also exist.[53]
Large-scale, offshore and distributed[edit]
Agile software development has been widely seen as highly suited to certain types of environments, including small teams of experts working on greenfield projects,[37][54]:157 and the challenges and limitations encountered in the adoption of agile software development methods in a large organization with legacy infrastructure are well-documented and understood.[55]
In response, a range of strategies and patterns has evolved for overcoming challenges with large-scale development efforts (>20 developers)[56][57] or distributed (non-colocated) development teams,[58][59] amongst other challenges; and there are now several recognised frameworks that seek to mitigate or avoid these challenges.
- Scaled agile framework (SAFe),[60] Dean Leffingwell et al
- Disciplined agile delivery (DAD), Scott Ambleret al
- Large-scale scrum (LeSS), Craig Larman and Bas Vodde
- Nexus (scaled professional Scrum),[61]Ken Schwaber
- Scrum at Scale,[62]Jeff Sutherland, Alex Brown
- Enterprise Scrum,[63]Mike Beedle
- Setchu (Scrum-based lightweight framework),[64] Michael Ebbage
- Xscale[65]
- Agile path[66]
- Holistic Software Development [67]
There are many conflicting viewpoints on whether all of these are effective or indeed fit the definition of agile development, and this remains an active and ongoing area of research.[56][68]
When agile software development is applied in a distributed setting (with teams dispersed across multiple business locations), it is commonly referred to as distributed agile development. The goal is to leverage the unique benefits offered by each approach. Distributed development allow organizations to build software by strategically setting up teams in different parts of the globe, virtually building software round-the-clock (more commonly referred to as follow-the-sun model). On the other hand, agile development provides increased transparency, continuous feedback and more flexibility when responding to changes.
Regulated domains[edit]
Agile software development methods were initially seen as best suitable for non-critical product developments, thereby excluded from use in regulated domains such as medical devices, pharmaceutical, financial, nuclear systems, automotive, and avionics sectors, etc. However, in the last several years, there have been several initiatives for the adaptation of agile methods for these domains.[69][70][71][72][73]
There are numerous standards that may apply in regulated domains, including ISO 26262, ISO 9000, ISO 9001, and ISO/IEC 15504.A number of key concerns are of particular importance in regulated domains:[74]
- Quality assurance (QA): Systematic and inherent quality management underpinning a controlled professional process and reliability and correctness of product.
- Safety and security: Formal planning and risk management to mitigate safety risks for users and securely protecting users from unintentional and malicious misuse.
- Traceability: Documentation providing auditable evidence of regulatory compliance and facilitating traceability and investigation of problems.
- Verification and Validation (V&V): Embedded throughout the software development process (e.g. user requirements specification, functional specification, design specification, code review, unit tests, integration tests, system tests).
Experience and adoption[edit]
Although agile software development methods can be used with any programming paradigm or language in practice, they were originally closely associated with object-oriented environments such as Smalltalk and Lisp and later Java. The initial adopters of agile methods were usually small to medium-sized teams working on unprecedented systems with requirements that were difficult to finalize and likely to change as the system was being developed. This section describes common problems that organizations encounter when they try to adopt agile software development methods as well as various techniques to measure the quality and performance of agile teams.[75]
Measuring agility[edit]
The best agile practitioners have always emphasized thorough engineering principles. As a result, there are a number of best practices and tools for measuring the performance of agile software development and teams.
Internal assessments[edit]
The Agility measurement index, amongst others, rates developments against five dimensions of product development (duration, risk, novelty, effort, and interaction).[76][77] Other techniques are based on measurable goals[78] and one study suggests that velocity can be used as a metric of agility.[79] There are also agile self-assessments to determine whether a team is using agile software development practices (Nokia test,[80] Karlskrona test,[81] 42 points test).[82]
Public surveys[edit]
One of the early studies reporting gains in quality, productivity, and business satisfaction by using agile software developments methods was a survey conducted by Shine Technologies from November 2002 to January 2003.[83]
A similar survey, the State of Agile, is conducted every year starting in 2006 with thousands of participants from around the software development community. This tracks trends on the benefits of agility, lessons learned, and good practices. Each survey has reported increasing numbers saying that agile software development helps them deliver software faster; improves their ability to manage changing customer priorities; and increases their productivity.[84] Surveys have also consistently shown better results with agile product development methods compared to classical project management.[85][86] In balance, there are reports that some feel that agile development methods are still too young to enable extensive academic research of their success.[87]
The new version shortens your time to market, for example by means of simulation tools, increases the productivity of your plant through additional diagnostics and energy management functions, and offers you broader flexibility by connecting to the management level. The new options benefit system integrators and machine builders as well as plant operators. Tia v13 sp1 download.
Common agile software development pitfalls[edit]
Organizations and teams implementing agile software development often face difficulties transitioning from more traditional methods such as waterfall development, such as teams having an agile process forced on them.[88] These are often termed agile anti-patterns or more commonly agile smells. Below are some common examples:
Lack of overall product design[edit]
A goal of agile software development is to focus more on producing working software and less on documentation. This is in contrast to waterfall models where the process is often highly controlled and minor changes to the system require significant revision of supporting documentation. However, this does not justify completely doing without any analysis or design at all. Failure to pay attention to design can cause a team to proceed rapidly at first but then to have significant rework required as they attempt to scale up the system. One of the key features of agile software development is that it is iterative. When done correctly design emerges as the system is developed and commonalities and opportunities for re-use are discovered.[89]
Adding stories to an iteration in progress[edit]
In agile software development, stories (similar to use case descriptions) are typically used to define requirements and an iteration is a short period of time during which the team commits to specific goals.[90] Adding stories to an iteration in progress is detrimental to a good flow of work. These should be added to the product backlog and prioritized for a subsequent iteration or in rare cases the iteration could be cancelled.[91]
This does not mean that a story cannot expand. Teams must deal with new information, which may produce additional tasks for a story. If the new information prevents the story from being completed during the iteration, then it should be carried over to a subsequent iteration. However, it should be prioritized against all remaining stories, as the new information may have changed the story's original priority.
Lack of sponsor support[edit]
Agile software development is often implemented as a grassroots effort in organizations by software development teams trying to optimize their development processes and ensure consistency in the software development life cycle. By not having sponsor support, teams may face difficulties and resistance from business partners, other development teams and management. Additionally, they may suffer without appropriate funding and resources.[92] This increases the likelihood of failure.[93]
Insufficient training[edit]
A survey performed by VersionOne found respondents cited insufficient training as the most significant cause for failed agile implementations[94] Teams have fallen into the trap of assuming the reduced processes of agile software development compared to other methodologies such as waterfall means that there are no actual rules for agile software development.[citation needed]
Product owner role is not properly filled[edit]
The product owner is responsible for representing the business in the development activity and is often the most demanding role.[95]
Please select your specific HP printer. You will only be able to print. 05) Click on the “Use” drop-down menu and select your printer model. Do NOT select AirPrint.Make sure that you do NOT select AirPrint. If you select AirPrint, then you won’t be able to use any of your HP printer’s extra features like scanning and faxing.
A common mistake is to have the product owner role filled by someone from the development team. This requires the team to make its own decisions on prioritization without real feedback from the business. They try to solve business issues internally or delay work as they reach outside the team for direction. This often leads to distraction and a breakdown in collaboration.[96]
Teams are not focused[edit]
Agile software development requires teams to meet product commitments, which means they should focus only on work for that product. However, team members who appear to have spare capacity are often expected to take on other work, which makes it difficult for them to help complete the work to which their team had committed.[97]
Excessive preparation/planning[edit]
Teams may fall into the trap of spending too much time preparing or planning. This is a common trap for teams less familiar with agile software development where the teams feel obliged to have a complete understanding and specification of all stories. Teams should be prepared to move forward only with those stories in which they have confidence, then during the iteration continue to discover and prepare work for subsequent iterations (often referred to as backlog refinement or grooming).
Problem-solving in the daily standup[edit]
A daily standup should be a focused, timely meeting where all team members disseminate information. If problem-solving occurs, it often can only involve certain team members and potentially is not the best use of the entire team's time. If during the daily standup the team starts diving into problem-solving, it should be set aside until a sub-team can discuss, usually immediately after the standup completes. [98]
Assigning tasks[edit]
One of the intended benefits of agile software development is to empower the team to make choices, as they are closest to the problem. Additionally, they should make choices as close to implementation as possible, to use more timely information in the decision. If team members are assigned tasks by others or too early in the process, the benefits of localized and timely decision making can be lost.[99]
Being assigned work also constrains team members into certain roles (for example, team member A must always do the database work), which limits opportunities for cross-training.[99] Team members themselves can choose to take on tasks that stretch their abilities and provide cross-training opportunities.
Scrum master as a contributor[edit]
Another common pitfall is for a scrum master to act as a contributor. While not prohibited by the Scrum methodology, the scrum master needs to ensure they have the capacity to act in the role of scrum master first and not working on development tasks. A scrum master's role is to facilitate the process rather than create the product.[100]
Having the scrum master also multitasking may result in too many context switches to be productive. Additionally, as a scrum master is responsible for ensuring roadblocks are removed so that the team can make forward progress, the benefit gained by individual tasks moving forward may not outweigh roadblocks that are deferred due to lack of capacity.[100]
Lack of test automation[edit]
Due to the iterative nature of agile development, multiple rounds of testing are often needed. Automated testing helps reduce the impact of repeated unit, integration, and regression tests and frees developers and testers to focus on higher value work.[101]
Test automation also supports continued refactoring required by iterative software development. Allowing a developer to quickly run tests to confirm refactoring has not modified the functionality of the application may reduce the workload and increase confidence that cleanup efforts have not introduced new defects.
Allowing technical debt to build up[edit]
Focusing on delivering new functionality may result in increased technical debt. The team must allow themselves time for defect remediation and refactoring. Technical debt hinders planning abilities by increasing the amount of unscheduled work as production defects distract the team from further progress.[102]
As the system evolves it is important to refactor as entropy of the system naturally increases.[103] Over time the lack of constant maintenance causes increasing defects and development costs.[102]
Attempting to take on too much in an iteration[edit]
A common misconception is that agile software development allows continuous change, however an iteration backlog is an agreement of what work can be completed during an iteration.[104] Having too much work-in-progress (WIP) results in inefficiencies such as context-switching and queueing.[105] The team must avoid feeling pressured into taking on additional work.[106]
Fixed time, resources, scope, and quality[edit]
Agile software development fixes time (iteration duration), quality, and ideally resources in advance (though maintaining fixed resources may be difficult if developers are often pulled away from tasks to handle production incidents), while the scope remains variable. The customer or product owner often push for a fixed scope for an iteration. However, teams should be reluctant to commit to the locked time, resources and scope (commonly known as the project management triangle). Efforts to add scope to the fixed time and resources of agile software development may result in decreased quality.[107]
Developer burnout[edit]
Due to the focused pace and continuous nature of agile practices, there is a heightened risk of burnout among members of the delivery team.[108]
Agile management[edit]
The term agile management is applied to an iterative, incremental method of managing the design and build activities of engineering, information technology and other business areas that aim to provide new product or service development in a highly flexible and interactive manner, based on the principles expressed in the Manifesto for Agile Software Development.[109]
Agile X techniques may also be called extreme project management. It is a variant of iterative life cycle[110] where deliverables are submitted in stages. The main difference between agile and iterative development is that agile methods complete small portions of the deliverables in each delivery cycle (iteration),[111] while iterative methods evolve the entire set of deliverables over time, completing them near the end of the project. Both iterative and agile methods were developed as a reaction to various obstacles that developed in more sequential forms of project organization. For example, as technology projects grow in complexity, end users tend to have difficulty defining the long-term requirements without being able to view progressive prototypes. Projects that develop in iterations can constantly gather feedback to help refine those requirements.
Agile management also offers a simple framework promoting communication and reflection on past work amongst team members.[112] Teams who were using traditional waterfall planning and adopted the agile way of development typically go through a transformation phase and often take help from agile coaches who help guide the teams through a smooth transformation. There are typically two styles of agile coaching: push-based and pull-based agile coaching. Agile management approaches have also been employed and adapted to the business and government sectors. For example, within the federal government of the United States, the United States Agency for International Development (USAID) is employing a collaborative project management approach that focuses on incorporating collaborating, learning and adapting (CLA) strategies to iterate and adapt programming.[113]
Agile methods are mentioned in the Guide to the Project Management Body of Knowledge (PMBOK Guide) under the Project Lifecycle definition:
Adaptive project life cycle, a project life cycle, also known as change-driven or agile methods, that is intended to facilitate change and require a high degree of ongoing stakeholder involvement. Adaptive life cycles are also iterative and incremental, but differ in that iterations are very rapid (usually 2-4 weeks in length) and are fixed in time and resources.[114]
Applications outside software development[edit]
Agile Brazil 2014 conference
According to Jean-Loup Richet (Research Fellow at ESSEC Institute for Strategic Innovation & Services) 'this approach can be leveraged effectively for non-software products and for project management in general, especially in areas of innovation and uncertainty.' The end result is a product or project that best meets current customer needs and is delivered with minimal costs, waste, and time, enabling companies to achieve bottom line gains earlier than via traditional approaches.[115]
Agile software development methods have been extensively used for development of software products and some of them use certain characteristics of software, such as object technologies.[116] However, these techniques can be applied to the development of non-software products, such as computers, motor vehicles,[117] medical devices, food, clothing, and music.[118] Agile software development methods have been used in non-development IT infrastructuredeployments and migrations. Some of the wider principles of agile software development have also found application in general management[119] (e.g., strategy, governance, risk, finance) under the terms business agility or agile business management.
Under an agile business management model, agile software development techniques, practices, principles and values are expressed across five domains.[120]
- Integrated customer engagement: to embed customers within any delivery process to share accountability for product/service delivery.
- Facilitation-based management: adopting agile management models, like the role of Scrum Master, to facilitate the day-to-day operation of teams.
- Agile work practices: adopting specific iterative and incremental work practices such as Scrum, Kanban, test-driven development or feature-driven development across all business functions (from sales, human resources, finance[121] and marketing).
- An enabling organisational structure: with a focus on staff engagement, personal autonomy and outcomes based governance.
- Applications of agile process (along with DevOps and lean manufacturing), to data analytics, business intelligence, big data, and data science is called DataOps
Agile software development paradigms can be used in other areas of life such as raising children. Its success in child development might be founded on some basic management principles; communication, adaptation, and awareness. In a TED Talk, Bruce Feiler shared how he applied basic agile paradigms to household management and raising children.[122]
Criticism[edit]
Agile practices can be inefficient in large organizations and certain types of developments.[123] Many organizations believe that agile software development methodologies are too extreme and adopt a Hybrid approach [124] that mixes elements of agile software development and plan-driven approaches.[125] Some methods, such as dynamic systems development method (DSDM) attempt this in a disciplined way, without sacrificing fundamental principles.
The increasing adoption of agile practices has also been criticized as being a management fad that simply describes existing good practices under new jargon, promotes a one size fits all mindset towards development strategies, and wrongly emphasizes method over results.[126]
Alistair Cockburn organized a celebration of the 10th anniversary of the Manifesto for Agile Software Development in Snowbird, Utah on 12 February 2011, gathering some 30+ people who had been involved at the original meeting and since. A list of about 20 elephants in the room ('undiscussable' agile topics/issues) were collected, including aspects: the alliances, failures and limitations of agile software development practices and context (possible causes: commercial interests, decontextualization, no obvious way to make progress based on failure, limited objective evidence, cognitive biases and reasoning fallacies), politics and culture.[127] As Philippe Kruchten wrote:
The agile movement is in some ways a bit like a teenager: very self-conscious, checking constantly its appearance in a mirror, accepting few criticisms, only interested in being with its peers, rejecting en bloc all wisdom from the past, just because it is from the past, adopting fads and new jargon, at times cocky and arrogant. But I have no doubts that it will mature further, become more open to the outside world, more reflective, and therefore, more effective.
— Philippe Kruchten[127]
See also[edit]
References[edit]
What Is Agile Software Development Pdf
- ^Collier, Ken W. (2011). Agile Analytics: A Value-Driven Approach to Business Intelligence and Data Warehousing. Pearson Education. pp. 121 ff. ISBN9780321669544.
What is a self-organizing team?
- ^'What is Agile Software Development?'. Agile Alliance. 8 June 2013. Retrieved 4 April 2015.
- ^Rally (2010). 'Agile With a Capital 'A' Vs. agile With a Lowercase 'a''. Archived from the original on 5 January 2016. Retrieved 9 September 2015.CS1 maint: unfit url (link)
- ^ abcKent Beck; James Grenning; Robert C. Martin; Mike Beedle; Jim Highsmith; Steve Mellor; Arie van Bennekum; Andrew Hunt; Ken Schwaber; Alistair Cockburn; Ron Jeffries; Jeff Sutherland; Ward Cunningham; Jon Kern; Dave Thomas; Martin Fowler; Brian Marick (2001). 'Manifesto for Agile Software Development'. Agile Alliance. Retrieved 14 June 2010.
- ^Which is better – Kanban or Scrum?, 4 March 2016
- ^ abLarman, Craig (2004). Agile and Iterative Development: A Manager's Guide. Addison-Wesley. p. 27. ISBN978-0-13-111155-4.
- ^Dybå, Tore; Dingsøyr, Torgeir (1 August 2008). 'Empirical studies of agile software development: A systematic review'. Information and Software Technology. 50 (9–10): 833–859. doi:10.1016/j.infsof.2008.01.006. ISSN0950-5849.
- ^Lee, Gwanhoo; Xia, Weidong (2010). 'Toward Agile: An Integrated Analysis of Quantitative and Qualitative Field Data on Software Development Agility'. MIS Quarterly. 34 (1): 87–114. doi:10.2307/20721416. JSTOR20721416.
- ^Gerald M. Weinberg, as quoted in Larman & Basili 2003, pp. 47–56 'We were doing incremental development as early as 1957 in Los Angeles, under the direction of Bernie Dimsdale at IBM's Service Bureau Corporation. He was a colleague of John von Neumann, so perhaps he learned it there, or assumed it as totally natural. I do remember Herb Jacobs (primarily, though we all participated) developing a large simulation for Motorola, where the technique used was, as far as I can tell .. All of us, as far as I can remember, thought waterfalling of a huge project was rather stupid, or at least ignorant of the realities. I think what the waterfall description did for us was make us realize that we were doing something else, something unnamed except for 'software development.'
- ^'Evolutionary Project Management (Original page, external archive)'. Gilb. Archived from the original on 27 March 2016. Retrieved 30 April 2017.
- ^'Evolutionary Project Management (New page)'. Gilb. Retrieved 30 April 2017.
- ^Edmonds, E. A. (1974). 'A Process for the Development of Software for Nontechnical Users as an Adaptive System'. General Systems. 19: 215–18.
- ^Gilb, Tom (1 April 1981). 'Evolutionary development'. ACM SIGSOFT Software Engineering Notes. 6 (2): 17. doi:10.1145/1010865.1010868.
- ^Martin, James (1991). Rapid Application Development. Macmillan. ISBN978-0-02-376775-3.
- ^Kerr, James M.; Hunter, Richard (1993). Inside RAD: How to Build a Fully Functional System in 90 Days or Less. McGraw-Hill. p. 3. ISBN978-0-07-034223-1.
- ^Iacocca Institute (1991). '21st Century Manufacturing Enterprise Strategy: An Industry Led View'. Iacocca Institute, Lehigh University, Bethlehem, PA.
- ^Presley, A., J. Mills and D. Liles (1995). 'Agile Aerospace Manufacturing'. Nepcon East 1995, Boston.
- ^Anderson, David (2005). 'Declaration of Interdependence'. Archived from the original on 27 January 2018. Retrieved 4 October 2018.
- ^McDonald, Kent (1 November 2016). 'How You Can Help Agile Alliance Help You'. Agile Alliance Blog. Retrieved 4 July 2017.
- ^'Examining the Agile Manifesto'. Ambysoft Inc. Retrieved 6 April 2011.
- ^Jim Highsmith (2001). 'History: The Agile Manifesto'. agilemanifesto.org.
- ^ abKent Beck; James Grenning; Robert C. Martin; Mike Beedle; Jim Highsmith; Steve Mellor; Arie van Bennekum; Andrew Hunt; Ken Schwaber; Alistair Cockburn; Ron Jeffries; Jeff Sutherland; Ward Cunningham; Jon Kern; Dave Thomas; Martin Fowler; Brian Marick (2001). 'Principles behind the Agile Manifesto'. Agile Alliance. Archived from the original on 14 June 2010. Retrieved 6 June 2010.
- ^Moran, A. (2014). Agile Risk Management. Springer Verlag. ISBN978-3319050072.
- ^Beck, Kent (1999). 'Embracing Change with Extreme Programming'. Computer. 32 (10): 70–77. doi:10.1109/2.796139.
- ^Preuss, Deborah Hartmann (13 October 2006). 'Study: Co-Located Teams vs. the Cubicle Farm'. InfoQ. Retrieved 23 October 2018.
- ^Cockburn, Alistair (2007). 'Agile Software Development: The Cooperative Game'. www.pearson.com (2nd ed.). Addison-Wesley Professional. Retrieved 23 October 2018.
- ^Cockburn, Alistair (19 June 2008). 'Information radiator'.
- ^Ambler, Scott (12 April 2002). Agile Modeling: Effective Practices for EXtreme Programming and the Unified Process. John Wiley & Sons. pp. 12, 164, 363. ISBN978-0-471-20282-0.
- ^Vasiliauskas, Vidas (2014). 'Developing agile project task and team management practices'. Eylean. Archived from the original on 15 September 2014. Retrieved 15 September 2014.
- ^Jeffries, Ron; Anderson, Ann; Hendrickson, Chet (2001). Extreme Programming installed. Addison-Weslsy. pp. 72–147. ISBN978-0201-70842-4.
- ^Lisa Crispin; Janet Gregory (2009). Agile Testing: A Practical Guide for Testers and Agile Teams. Addison-Wesley.
- ^Mitchell, Ian (2016). Agile Development in Practice. Tamare House. p. 11. ISBN978-1-908552-49-5.
- ^Larman, Craig (2004). Agile and Iterative Development: A Manager's Guide. Addison-Wesley. p. 27. ISBN978-0-13-111155-4.
- ^Boehm, B.; R. Turner (2004). Balancing Agility and Discipline: A Guide for the Perplexed. Boston, MA: Addison-Wesley. ISBN978-0-321-18612-6. Appendix A, pages 165–194
- ^Larman, Craig (2004). 'Chapter 11: Practice Tips'. Agile and Iterative Development: A Manager's Guide. p. 253. ISBN9780131111554. Retrieved 14 October 2013.
- ^Sliger, Michele; Broderick, Stacia (2008). The Software Project Manager's Bridge to Agility. Addison-Wesley. p. 46. ISBN978-0-321-50275-9.
- ^ abBoehm, B.; R. Turner (2004). Balancing Agility and Discipline: A Guide for the Perplexed. Boston, MA: Addison-Wesley. pp. 55–57. ISBN978-0-321-18612-6.
- ^'At the Kickoff: Project Development vs Product Development'. AltexSoft Inc. 12 February 2016. Retrieved 31 May 2016.
- ^Rakitin, Steven R. (2001). 'Manifesto Elicits Cynicism: Reader's letter to the editor by Steven R. Rakitin'. IEEE Computer. 34: 4.
The article titled 'Agile Software Development: The Business of Innovation' .. is yet another attempt to undermine the discipline of software engineering .. We want to spend all our time coding. Remember, real programmers don't write documentation.
- ^ abScott Ambler. 'Agile/Lean Documentation: Strategies for Agile Software Development'.
- ^Scott Ambler. 'Just Barely Good Enough Models and Documents: An Agile Best Practice'.
- ^Geoffrey Wiseman (18 July 2007). 'Do Agile Methods Require Documentation?'. InfoQ. quoting Cooper, Ian (6 July 2007). 'Staccato Signals:Agile and Documentation'. WordPress.com.
- ^ abcAbrahamson P, Salo O, Ronkainen J, Warsta J (2002). Agile software development methods: Review and analysis(PDF) (Technical report). VTT. 478.
- ^'Guide to Agile Practices'. the Agile Alliance. Archived from the original on 9 February 2014.
- ^ abAydin, M.N.; Harmsen, F.; Slooten; Stagwee, R. A. (2004). 'An Agile Information Systems Development Method in use'. Turk J Elec Engin. 12 (2): 127–138.
- ^Morris, David (2015). The Paradox of Agile Transformation: Why trying too hard to be Agile stops organisations from becoming truly agile. NZ: University of Auckland. doi:10.13140/RG.2.2.32698.08640.
- ^Abrahamsson, P., Warsta, J., Siponen, M.T., & Ronkainen, J. (2003). New Directions on Agile Methods: A Comparative Analysis. Proceedings of ICSE'03, 244-254
- ^Mirakhorli, M.; Rad, A.K.; Shams, F.; Pazoki, M.; Mirakhorli, A. (2008). 'RDP technique: a practice to customize xp'. Proceedings of the 2008 international workshop on Scrutinizing agile practices or shoot-out at the agile corral (APOS '08). ACM. pp. 23–32. doi:10.1145/1370143.1370149. ISBN978-1-60558-021-0.
- ^Aydin, M.N.; Harmsen, F.; van Slooten, K.; Stegwee, R.A. (2005). 'On the Adaptation of An Agile Information(Suren) Systems Development Method'. Journal of Database Management. 16 (4): 20–24. doi:10.4018/jdm.2005100102.
- ^Schwaber, K (2006) Scrum is hard and disruptive.
- ^Vodde, B (2016) The Story of LeSS. Closing Keynote. Scrum Australia, Melbourne. April, 2016.
- ^Lagstedt, A., and Dahlberg, T. (2018). Understanding the Rarity of ISD Method Selection – Bounded Rationality and Functional Stupidity. PACIS 2018 Proceedings. 154. https://aisel.aisnet.org/pacis2018/154.
- ^Park, J. S., McMahon, P. E., and Myburgh, B. (2016). Scrum Powered by Essence. ACM SIGSOFT Software Engineering Notes, 41(1), pp. 1-8.
- ^Beck, K. (1999). Extreme Programming Explained: Embrace Change. Boston, MA: Addison-Wesley. ISBN978-0-321-27865-4.
- ^Evans, Ian. 'Agile Delivery at British Telecom'. Retrieved 21 February 2011.
- ^ abW. Scott Ambler (2006) Supersize Me in Dr. Dobb's Journal, 15 February 2006.
- ^Schaaf, R.J. (2007). Agility XL Systems and Software Technology Conference 2007Archived 13 March 2016 at the Wayback Machine, Tampa, FL
- ^'Bridging the Distance'. Sdmagazine.com. Retrieved 1 February 2011.
- ^Fowler, Martin. 'Using an Agile Software Process with Offshore Development'. Martinfowler.com. Retrieved 6 June 2010.
- ^Leffingwell, Dean. 'Scaled Agile Framework'. Scaled Agile Framework.
- ^Schwaber, Ken. 'Nexus Guide: The Definitive Guide to Nexus: The exoskeleton of scaled Scrum development'(PDF). scrum.org. Retrieved 14 September 2015.
- ^Sutherland, Jeff; Brown, Alex (23 July 2014). 'Scrum At Scale: Part 1'. Retrieved 14 September 2015.
- ^Beedle, Mike. 'Enterprise Scrum'. Retrieved 25 September 2015.
- ^Ebbage, Michael. 'Setchu – Agile at Scale'. Retrieved 30 September 2015.
- ^'XSCALE Alliance'. Agiletng.org. Retrieved 26 March 2019.
- ^'Agilepath – Collaborate.Innovate.Succeed'. Agile-path.com. 18 January 2019. Retrieved 26 March 2019.
- ^'Archived copy'. Archived from the original on 28 December 2018. Retrieved 18 September 2019.CS1 maint: archived copy as title (link)
- ^Agile Processes Workshop II Managing Multiple Concurrent Agile Projects. Washington: OOPSLA 2002
- ^Cawley, Oisín; Wang, Xiaofeng; Richardson, Ita (2010). Abrahamsson, Pekka; Oza, Nilay (eds.). Lean/Agile Software Development Methodologies in Regulated Environments – State of the Art. Lean Enterprise Software and Systems. Lecture Notes in Business Information Processing. 65. pp. 31–36. doi:10.1007/978-3-642-16416-3_4. hdl:10344/683. ISBN978-3-642-16415-6.
- ^McHugh, Martin; McCaffery, Fergal; Coady, Garret (4 November 2014). Mitasiunas, Antanas; Rout, Terry; O'Connor, Rory V.; et al. (eds.). An Agile Implementation within a Medical Device Software Organisation. Software Process Improvement and Capability Determination. Communications in Computer and Information Science. 477. pp. 190–201. doi:10.1007/978-3-319-13036-1_17. ISBN978-3-319-13035-4.
- ^Wang, Yang; Ramadani, Jasmin; Wagner, Stefan (29 November 2017). An Exploratory Study on Applying a Scrum Development Process for Safety-Critical Systems. Product-Focused Software Process Improvement. Lecture Notes in Computer Science. 10611. pp. 324–340. arXiv:1703.05375. Bibcode:2017arXiv170305375W. doi:10.1007/978-3-319-69926-4_23. ISBN9783319699257.
- ^'SafeScrum - SINTEF'. Sintef.no. Retrieved 26 March 2019.
- ^Thor Myklebust, Tor Stålhane, Geir Kjetil Hanssen, Tormod Wien and Børge Haugset: Scrum, documentation and the IEC 61508-3:2010 software standard, http://www.sintef.no/globalassets/ec-61508-documentation-and-safescrum-psam12.pdf
- ^Fitzgerald, B.; Stol, K.-J.; O'Sullivan, R.; O'Brien, D. (May 2013). Scaling agile methods to regulated environments: An industry case study. 2013 35th International Conference on Software Engineering (ICSE). pp. 863–872. doi:10.1109/ICSE.2013.6606635. hdl:10344/3055. ISBN978-1-4673-3076-3.
- ^Beck, Kent (2000). Extreme Programming Explained. Addison-Wesley. pp. 1–24. ISBN978-0201616415.
- ^Datta, Subhajit (2006). 'Agility measurement index: a metric for the crossroads of software development methodologies'. ACM-SE 44 Proceedings of the 44th annual Southeast regional conference. p. 271. doi:10.1145/1185448.1185509. ISBN1595933158.
- ^'David Bock's Weblog : Weblog'. Jroller.com. Archived from the original on 11 January 2006. Retrieved 2 April 2010.
- ^Peter Lappo; Henry C.T. Andrew. 'Assessing Agility'(PDF). Retrieved 6 June 2010.
- ^Kurian, Tisni (2006). Agility Metrics: A Quantitative Fuzzy Based Approach for Measuring Agility of a Software Process, ISAM-Proceedings of International Conference on Agile Manufacturing'06(ICAM-2006), Norfolk, U.S.
- ^Joe Little (2 December 2007). 'Nokia test, A scrum-specific test'. Agileconsortium.blogspot.com. Retrieved 6 June 2010.
- ^Mark Seuffert; Mayberg, Sweden. 'Karlskrona test, A generic agile adoption test'. Mayberg.se. Retrieved 5 April 2014.
- ^'How Agile Are You? (Take This 42 Point Test)'. allaboutagile.com/. Archived from the original on 5 May 2014. Retrieved 3 April 2014.
- ^'Agile Methodologies Survey Results'(PDF). Shine Technologies. January 2003. Archived from the original(PDF) on 21 August 2010. Retrieved 3 June 2010.
95% stated that there was either no effect or a cost reduction .. 93% stated that productivity was better or significantly better .. 88% stated that quality was better or significantly better .. 83% stated that business satisfaction was better or significantly better
- ^'2013 State of Agile report: Why Agile?'. stateofagile.com. 27 January 2014. Archived from the original on 28 August 2014. Retrieved 13 August 2014.
- ^Status Quo Agile, Second study on success and forms of usage of agile methods. Retrieved 1 July 2015
- ^Ambler, Scott (3 August 2006). 'Survey Says: Agile Works in Practice'. Dr. Dobb's. Retrieved 3 June 2010.
Only 6% indicated that their productivity was lowered .. No change in productivity was reported by 34% of respondents and 60% reported increased productivity .. 66% [responded] that the quality is higher .. 58% of organizations report improved satisfaction, whereas only 3% report reduced satisfaction.
- ^'Answering the 'Where is the Proof That Agile Methods Work' Question'. Agilemodeling.com. 19 January 2007. Retrieved 2 April 2010.
- ^Shore & Warden 2008, p. 47
- ^Beck, Kent (2000). Extreme Programming Explained. Addison-Wesley. pp. 48–49. ISBN978-0201616415.
- ^Rouse, Margaret. 'Sprint (software development) definition'. searchsoftwarequality.techtarget.com. Retrieved 2 October 2015.
- ^Goldstein, Ilan (11 October 2011). 'Sprint issues – when sprints turn into crawls'. www.axisagile.com.au. Retrieved 8 June 2014.
- ^'Project Roles and Responsibility Distribution'. agile-only.com. Retrieved 15 June 2014.
- ^Bourne, Lynda. 'What Does a Project Sponsor Really Do?'. blogs.pmi.org. Retrieved 8 June 2014.
- ^'9th State of Agile Report'. Stage of Agile Survey. VersionOne. Archived from the original on 12 January 2015. Retrieved 8 June 2014.
- ^Sims, Chris; Johnson, Hillary Louise (15 February 2011). The Elements of Scrum (Kindle ed.). Dymaxicon. p. 73.
- ^Rothman, Johanna Rothman (25 August 2011). 'When You Have No Product Owner At All'. www.jrothman.com. Retrieved 8 June 2014.
- ^Fox, Alyssa (8 April 2014). 'Working on Multiple Agile Teams'. techwhirl.com/. Retrieved 14 June 2014.
- ^'Daily Scrum Meeting'. www.mountaingoatsoftware.com. Retrieved 14 June 2014.
- ^ abMay, Robert. 'Effective Sprint Planning'. www.agileexecutives.org. Archived from the original on 28 June 2014. Retrieved 14 June 2014.
- ^ abBerczuk, Steve. 'Mission Possible: ScrumMaster and Technical Contributor'. www.agileconnection.com. Retrieved 14 June 2014.
- ^Namta, Rajneesh. 'Thoughts on Test Automation in Agile'. www.infoq.com. Retrieved 14 June 2014.
- ^ abBand, Zvi (22 March 2014). 'Technical Debt + Red October'. Retrieved 8 June 2014.
- ^Shore, James. 'The Art of Agile Development: Refactoring'. www.jamesshore.com. Retrieved 14 June 2014.
- ^'Step 4: Sprint Planning (Tasks)'. www.allaboutagile.com. Archived from the original on 29 June 2014. Retrieved 14 June 2014.
- ^George, Claire. 'Why Limiting Your Work-in-Progress Matters'. leankit.com. Retrieved 14 June 2014.
- ^'Sprint Planning Meeting'. www.mountaingoatsoftware.com. Retrieved 14 June 2014.
- ^McMillan, Keith. 'Time, Resources, Scope.. and Quality'. www.adeptechllc.com. Retrieved 15 June 2014.
- ^'Current study on limitations of Agile'. Procedia Computer Science. 78: 291–297. January 2016. doi:10.1016/j.procs.2016.02.056.
- ^Moran, Alan (2015). Managing Agile: Strategy, Implementation, Organisation and People. Springer. ISBN978-3-319-16262-1.
- ^ExecutiveBrief, Which Life Cycle Is Best For Your Project?, PM Hut. Accessed 23 October 2009.
- ^'Agile Project Management'. VersionOne. Retrieved 1 June 2015.
- ^'What is Agile Management?'. Project Laneways. Retrieved 1 June 2015.
- ^USAID. 'ADS Chapter 201 Program Cycle Operational Policy'. Retrieved 19 April 2017
- ^Project Management Institute, A Guide to the Project Management Body of Knowledge (PMBOK Guide), Fifth Edition
- ^Richet, Jean-Loup (2013). Agile Innovation. Cases and Applied Research, n°31. ESSEC-ISIS. ISBN978-2-36456-091-8
- ^Smith, Preston G (2007). Flexible Product Development. Jossey-Bass. p. 25. ISBN978-0-7879-9584-3.
- ^'WIKISPEED – Applying Agile software principles and practices for fast automotive development'. Agile Business Management Consortium. 3 December 2013. Retrieved 11 September 2015.
- ^Newton Lee (2014). 'Getting on the Billboard Charts: Music Production as Agile Software Development,' Digital Da Vinci: Computers in Music. Springer Science+Business Media. ISBN978-1-4939-0535-5.
- ^Moran, Alan (2015). Managing Agile: Strategy, Implementation, Organisation and People. Springer Verlag. ISBN978-3-319-16262-1.
- ^Leybourn, Evan (2013). Directing the Agile Organisation: A Lean Approach to Business Management. IT Governance Publishing. ISBN978-1-849-28491-2.
- ^'Pair Trading: Collaboration in Finance'. The Agile Director. 11 March 2015. Retrieved 11 September 2015.
- ^'Agile programming – for your family'.
- ^Larman, Craig; Bas Vodde (13 August 2009). Top Ten Organizational Impediments to Large-Scale Agile Adoption. InformIT.
- ^'Introduction to Hybrid project management'. 20 July 2016.
- ^Barlow, Jordan B.; Justin Scott Giboney; Mark Jeffery Keith; David W. Wilson; Ryan M. Schuetzler; Paul Benjamin Lowry; Anthony Vance (2011). 'Overview and Guidance on Agile Development in Large Organizations'. Communications of the Association for Information Systems. 29 (1): 25–44. doi:10.17705/1CAIS.02902.
- ^Kupersmith, Kupe. 'Agile is a Fad'.
- ^ abKruchten, Philippe (20 June 2011). 'Agile's Teenage Crisis?'. InfoQ.
Further reading[edit]
- Abrahamsson, P.; Salo, O.; Ronkainen, J.; Warsta, J. (2002). 'Agile Software Development Methods: Review and Analysis'. VTT Publications. 478.
- Ashmore, Sondra; Runyan, Kristin (2014). Introduction to Agile Methods. Addison-Wesley. ISBN978-0321929563.
- Cohen, D.; Lindvall, M.; Costa, P. (2004). 'An introduction to agile methods'. In Zelkowitz, Marvin (ed.). Advances in Software Engineering. Advances in Computers. 62. Academic Press. pp. 1–66. ISBN978-0-08-047190-7.
- Dingsøyr, Torgeir; Dybå, Tore; Moe, Nils Brede (2010). Agile Software Development: Current Research and Future Directions. Springer. ISBN978-3-642-12575-1.
- Fowler, Martin (2001). 'Is Design Dead?'. In Succi, Giancarlo; Marchesi, Michele (eds.). Extreme Programming Examined. Addison-Wesley. pp. 3–18. ISBN978-0-201-71040-3.
- Larman, Craig; Basili, Victor R. (June 2003). 'Iterative and Incremental Development: A Brief History'(PDF). IEEE Computer. 36 (3): 47–56. doi:10.1109/MC.2003.1204375.
- Casagni, Michelle; Benito, Robert; Mayfield, Dr Kathleen M.; Northern, Carlton (8 September 2013). 'Handbook for Implementing Agile in Department of Defense Information Technology Acquisition'. The Mitre Corporation. MITRE.
- Moran, Alan (2015). Managing Agile: Strategy, Implementation, Organisation and People. Springer. ISBN978-3-319-16262-1.
- Riehle, Dirk. 'A Comparison of the Value Systems of Adaptive Software Development and Extreme Programming: How Methodologies May Learn From Each Other'. In Succi & Marchesi 2001
- Shore, James; Warden, Shane (2008). The Art of Agile Development. O'Reilly Media. ISBN978-0-596-52767-9.
- Stephens, M.; Rosenberg, D. (2003). Extreme Programming Refactored: The Case Against XP. Apress. ISBN978-1-59059-096-6.
External links[edit]
- The New MethodologyMartin Fowler's description of the background to agile methods
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Agile_software_development&oldid=917780455'
Software development |
---|
Core activities |
Paradigms and models |
Methodologies and frameworks |
Supporting disciplines |
Practices |
Tools |
Standards and Bodies of Knowledge |
Glossaries |
Scrum is an agile process framework for managing complex knowledge work, with an initial emphasis on software development, although it has been used in other fields and is slowly starting to be explored for other complex work, research and advanced technologies.[1] It is designed for teams of ten or fewer members, who break their work into goals that can be completed within timeboxed iterations, called sprints, no longer than one month and most commonly two weeks, then track progress and re-plan in 15-minute time-boxed stand-up meetings, called daily scrums.[2][3]
- 4Roles
- 5Workflow
- 6Artifacts
- 6.1Product backlog
- 6.4Extensions
- 10Adaptations
Key ideas[edit]
Scrum is a lightweight, iterative and incremental framework for managing complex work.[4][5] The framework challenges assumptions of the traditional, sequential approach to product development, and enables teams to self-organize by encouraging physical co-location or close online collaboration of all team members, as well as daily face-to-face communication among all team members and disciplines involved.
A key principle of Scrum is the dual recognition that customers will change their minds about what they want or need (often called requirements volatility[6]) and that there will be unpredictable challenges—for which a predictive or planned approach is not suited.
As such, Scrum adopts an evidence-based empirical approach — accepting that the problem cannot be fully understood or defined up front, and instead focusing on how to maximize the team's ability to deliver quickly, to respond to emerging requirements, and to adapt to evolving technologies and changes in market conditions.
Capitalization of Scrum[edit]
Scrum is occasionally seen written in all-capitals, as SCRUM.[7] The word is not an acronym, so this stylization is not correct; it likely arose due to an early paper by Ken Schwaber[8] which capitalized SCRUM in its title.[2][9]
While the trademark on the term Scrum itself has been allowed to lapse, it is deemed as owned by the wider community rather than an individual,[10] so the leading capital for Scrum is retained in this article.
Many of the terms used in Scrum are typically written with leading capitals (e.g., Scrum Master, Daily Scrum). However, to maintain an encyclopedic tone, this article uses normal sentence case for these terms (e.g., scrum master, daily scrum) — unless they are recognized marks (such as Certified Scrum Master).
History[edit]
Hirotaka Takeuchi and Ikujiro Nonaka introduced the term scrum in the context of product development in their 1986 Harvard Business Review article, 'The New New Product Development Game'.[11] Takeuchi and Nonaka later argued in The Knowledge Creating Company[12] that it is a form of 'organizational knowledge creation, [..] especially good at bringing about innovation continuously, incrementally and spirally'.
The authors described a new approach to commercial product development that would increase speed and flexibility, based on case studies from manufacturing firms in the automotive, photocopier and printer industries.[11] They called this the holistic or rugby approach, as the whole process is performed by one cross-functional team across multiple overlapping phases, in which the team 'tries to go the distance as a unit, passing the ball back and forth'.[11] (In rugby football, a scrum is used to restart play, as the forwards of each team interlock with their heads down and attempt to gain possession of the ball.[13])
The Scrum framework was based on research by Schwaber with Tunde Babatunde at DuPont Research Station and University of Delaware. Tunde advised that attempts to develop complex product, such as software, that weren’t based in empiricism were doomed to higher risks and rates of failure as the initial conditions and assumptions change. Empiricism, using frequent inspection and adaptation, with flexibility and transparency is the most suitable approach.
In the early 1990s, Ken Schwaber used what would become Scrum at his company, Advanced Development Methods; while Jeff Sutherland, John Scumniotales and Jeff McKenna developed a similar approach at Easel Corporation, referring to it using the single word scrum.[14]
Ken and Jeff worked together to integrate their ideas into a single framework, Scrum. They tested Scrum and continually improved it, leading to the 1995 paper, the Agile Manifesto in 2001, and the worldwide spread and use of Scrum since 2002.
In 1995, Sutherland and Schwaber jointly presented a paper describing the Scrum framework at the Business Object Design and Implementation Workshop held as part of Object-Oriented Programming, Systems, Languages & Applications '95 (OOPSLA '95) in Austin, Texas.[15] Over the following years, Schwaber and Sutherland collaborated to combine this material—with their experience and evolving good practice—to develop what became known as Scrum.[16]
In 2001, Schwaber worked with Mike Beedle to describe the method in the book, Agile Software Development with Scrum.[17] Scrum's approach to planning and managing product development involves bringing decision-making authority to the level of operation properties and certainties.[2]
In 2002, Schwaber with others founded the Scrum Alliance[18] and set up the Certified Scrum accreditation series. Schwaber left the Scrum Alliance in late 2009 and founded Scrum.org which oversees the parallel Professional Scrum accreditation series.[19]
Since 2009, a public document called The Scrum Guide[16] has been published and updated by Schwaber and Sutherland. It has been revised 5 times, with the current version being November 2017.
Roles[edit]
There are three roles in the Scrum framework.[20] These are ideally co-located to ensure optimal communication among team members. Together these three roles form the scrum team. While many organizations have other roles involved with defining and delivering the product, Scrum defines only these three.[16]
Product owner[edit]
The product owner, representing the product's stakeholders and the voice of the customer (or may represent the desires of a committee[21]), is responsible for delivering good business results. [22] Hence, the product owner is accountable for the product backlog and for maximizing the value that the team delivers.[21] The product owner defines the product in customer-centric terms (typically user stories), adds them to the product backlog, and prioritizes them based on importance and dependencies.[23] A scrum team should have only one product owner (although a product owner could support more than one team)[24] This role should not be combined with that of the scrum master. The product owner should focus on the business side of product development and spend the majority of their time liaising with stakeholders and the team. The product owner should not dictate how the team reaches a technical solution, but rather will seek consensus among the team members.[25][better source needed] This role is crucial and requires a deep understanding of both sides: the business and the engineers (developers) in the scrum team. Therefore a good product owner should be able to communicate what the business needs, ask why they need it (because there may be better ways to achieve that), and convey the message to all stakeholders including the delivery Team using a technical language, as required. The Product Owner uses Scrum’s empirical tools to manage highly complex work, while controlling risk and achieving value.
Communication is a core responsibility of the product owner. The ability to convey priorities and empathize with team members and stakeholders is vital to steer product development in the right direction. The product owner role bridges the communication gap between the team and its stakeholders, serving as a proxy for stakeholders to the team and as a team representative to the overall stakeholder community.[26][27]
As the face of the team to the stakeholders, the following are some of the communication tasks of the product owner to the stakeholders:[28]
- Define and announce releases.
- Communicate delivery and team status.
- Share progress during governance meetings.
- Share significant RIDAs (risks, impediments, dependencies, and assumptions) with stakeholders.
- Negotiate priorities, scope, funding, and schedule.
- Ensure that the product backlog is visible, transparent and clear.
Empathy is a key attribute for a product owner to have—the ability to put one's self in another's shoes. A product owner converses with different stakeholders, who have a variety of backgrounds, job roles, and objectives. A product owner must be able to see from these different points of view. To be effective, it is wise for a product owner to know the level of detail the audience needs. The development team needs thorough feedback and specifications so they can build a product up to expectation, while an executive sponsor may just need summaries of progress. Providing more information than necessary may lose stakeholder interest and waste time. A direct means of communication is the most preferred by seasoned agile product owners.[24]
A product owner's ability to communicate effectively is also enhanced by being skilled in techniques that identify stakeholder needs, negotiate priorities between stakeholder interests, and collaborate with developers to ensure effective implementation of requirements.
Development team[edit]
The development team has from three to nine members who carry out all tasks required to build increments of valuable output every sprint.[23]
While team members are referred to as developers in some literature[16], the term refers to anyone who plays a role in the development and support of the system or product, and can include researchers, architects, designers, data specialists, statisticians, analysts, engineers, programmers, and testers, among others.[20] However, due to the confusion that can arise when some people do not feel the term 'developer' applies to them, they are often referred to just as team members.
The team is self-organizing. While no work should come to the team except through the product owner, and the scrum master is expected to protect the team from too much distraction, the team should still be encouraged to interact directly with customers and/or stakeholders to gain maximum understanding and immediacy of feedback.[23]
Scrum master[edit]
Scrum is facilitated by a scrum master, who is accountable for removing impediments to the ability of the team to deliver the product goals and deliverables.[29] The scrum master is not a traditional team lead or project manager but acts as a buffer between the team and any distracting influences. The scrum master ensures that the scrum framework is followed. The scrum master helps to ensure the team follows the agreed processes in the Scrum framework, often facilitates key sessions, and encourages the team to improve. The role has also been referred to as a team facilitator[30] or servant-leader to reinforce these dual perspectives.
The core responsibilities of a scrum master include (but are not limited to):[31]
- Helping the product owner maintain the product backlog in a way that ensures the needed work is well understood so the team can continually make forward progress
- Helping the team to determine the definition of done for the product, with input from key stakeholders
- Coaching the team, within the Scrum principles, in order to deliver high-quality features for its product[32]
- Promoting self-organization within the team
- Helping the scrum team to avoid or remove impediments to its progress, whether internal or external to the team
- Facilitating team events to ensure regular progress
- Educating key stakeholders on Agile and Scrum principles
- Coaching the development team in self-organization and cross-functionality
The scrum master helps people and organizations adopt empirical and lean thinking, leaving behind hopes for certainty and predictability.
One of the ways the scrum master role differs from a project manager is that the latter may have people management responsibilities and the scrum master does not. A scrum master provides a limited amount of direction since the team is expected to be empowered and self-organizing.[33] Scrum does not formally recognise the role of project manager, as traditional command and control tendencies would cause difficulties.[34]
Workflow[edit]
Sprint[edit]
Scrum framework
The Scrum process
A sprint (also known as iteration or timebox) is the basic unit of development in Scrum. The sprint is a timeboxed effort; that is, the length is agreed and fixed in advance for each sprint and is normally between one week and one month, with two weeks being the most common.[2]
Each sprint starts with a sprint planning event that establishes a sprint goal and the required product backlog items. The team accepts what they agree is ready and translate this into a sprint backlog, with a breakdown of the work required and an estimated forecast for the sprint goal. Each sprint ends with a sprint review and sprint retrospective, that reviews progress to show to stakeholders and identify lessons and improvements for the next sprints.[14]
Scrum emphasizes valuable, useful output at the end of the sprint that is really done. In the case of software, this likely includes that the software has been fully integrated, tested and documented, and is potentially releasable.[34]
Sprint planning[edit]
At the beginning of a sprint, the scrum team holds a sprint planning event[35] to:
- Mutually discuss and agree on the scope of work that is intended to be done during that sprint
- Select product backlog items that can be completed in one sprint
- Prepare a sprint backlog that includes the work needed to complete the selected product backlog items
- Agree the sprint goal, a short description of what they are forecasting to deliver at the end of the sprint.
- The recommended duration is four hours for a two-week sprint (pro-rata for other sprint durations) [16]
- During the first half, the whole scrum team (development team, scrum master, and product owner) selects the product backlog items they believe could be completed in that sprint
- During the second half, the development team identifies the detailed work (tasks) required to complete those product backlog items; resulting in a confirmed sprint backlog
- As the detailed work is elaborated, some product backlog items may be split or put back into the product backlog if the team no longer believes they can complete the required work in a single sprint
- Once the development team has prepared their sprint backlog, they forecast (usually by voting) which tasks will be delivered within the sprint.
Daily scrum[edit]
A daily scrum in the computing room. This centralized location helps the team start on time.
Each day during a sprint, the team holds a daily scrum (or stand-up) with specific guidelines:
- All members of the development team come prepared. The daily scrum:
- starts precisely on time even if some development team members are missing
- should happen at the same time and place every day
- is limited (timeboxed) to fifteen minutes
- Anyone is welcome, though only development team members should contribute.
- During the daily scrum, each team member typically answers three questions:
- What did I complete yesterday that contributed to the team meeting our sprint goal?
- What do I plan to complete today to contribute to the team meeting our sprint goal?
- Do I see any impediment that could prevent me or the team from meeting our sprint goal?
Any impediment (e.g., stumbling block, risk, issue, delayed dependency, assumption proved unfounded)[36] identified in the daily scrum should be captured by the scrum master and displayed on the team's scrum board or on a shared risk board, with an agreed person designated to working toward a resolution (outside of the daily scrum). While the currency of work status is the whole team's responsibility, the scrum master often updates the sprint burndown chart.[37] Where the team does not see the value in these events, it is the responsibility of the scrum master to find out why.[38] This is part of the responsibility of educating the team and stakeholders about the Scrum principles.[32]
No detailed discussions should happen during the daily scrum. Once the meeting ends, members can (usually two or more) get together to discuss issues in detail and some call this as 'breakout sessions' or 'after party'.[37]
Sprint review[edit]
At the end of a sprint, the team holds two events: the sprint review and the sprint retrospective.
At the sprint review, the team:
- reviews the work that was completed and the planned work that was not completed
- presents the completed work to the stakeholders (a.k.a. the demo)
- collaborates with the stakeholders on what to work on next
Guidelines for sprint reviews:
- Incomplete work cannot be demonstrated.
- The recommended duration is two hours for a two-week sprint (proportional for other sprint-durations).[16]
Sprint retrospective[edit]
At the sprint retrospective, the team:
- Reflects on the past sprint
- Identifies and agrees on continuous process improvement actions
Guidelines for sprint retrospectives:
- Three main questions are asked in the sprint retrospective: What went well during the sprint? What did not go well? What could be improved for better productivity in the next sprint?
- The recommended duration is one-and-a-half hours for a two-week sprint (proportional for other sprint duration(s))
- This event is facilitated by the scrum master
Backlog refinement[edit]
Backlog refinement (formerly called grooming) is the ongoing process of reviewing product backlog items and checking that they are appropriately prepared and ordered in a way that makes them clear and executable for teams once they enter sprints via the sprint planning activity. Product backlog items may be broken into multiple smaller ones. Acceptance criteria may be clarified. Dependencies may be identified and investigated.
Although not originally a core Scrum practice, backlog refinement has been added to the Scrum Guide and adopted as a way of managing the quality of product backlog items entering a sprint, with a recommended investment of up to 10% of a team's sprint capacity.[16][39]
The backlog can also include technical debt (also known as design debt or code debt). This is a concept in software development that reflects the implied cost of additional rework caused by choosing an easy solution now instead of using a better approach that would take longer.
Cancelling a sprint[edit]
The product owner can cancel a sprint if necessary.[16] The product owner may do so with input from the team, scrum master or management. For instance, management may wish the product owner to cancel a sprint if external circumstances negate the value of the sprint goal. If a sprint is abnormally terminated, the next step is to conduct a new sprint planning, where the reason for the termination is reviewed.
Artifacts[edit]
Product backlog[edit]
The product backlog is a breakdown of work to be done[40] and contains an ordered list of product requirements that a scrum team maintains for a product. Common formats include user stories and use cases.[34] The requirements define features, bug fixes, non-functional requirements, etc.—whatever must be done to deliver a viable product. The product owner prioritizes product backlog items (PBIs) based on considerations such as risk, business value, dependencies, size, and date needed.
The product backlog is what will be delivered, ordered into the sequence in which it should be delivered. It is visible to everyone but may only be changed with the consent of the product owner, who is ultimately responsible for ordering product backlog items for the development team to choose.
The product backlog contains the product owner's assessment of business value and the development team's assessment of development effort, which are often, but not always, stated in story points using the rounded Fibonacci scale. These estimates help the product owner to gauge the timeline and may influence the ordering of product backlog items; for example, if two features have the same business value, the product owner may schedule earlier delivery of the one with the lower development effort (because the return on investment is higher) or the one with higher development effort (because it is more complex or riskier, and they want to retire that risk earlier).[41]
The product backlog and the business value of each product backlog item is the responsibility of the product owner. The effort to deliver each item is estimated by the development team in story points, or time. By estimating in story points, the team reduces the dependency in individual developers; this is useful especially in dynamic teams where developers are often assigned to other projects after sprint delivery. For instance, if a user story is estimated as a 5 in effort (using Fibonacci sequence), it remains 5 regardless of how many developers are working on it
Story points define the effort in a time-box, so they do not change with time. For instance, in one hour an individual can walk, run, or climb, but the effort expended is clearly different. The gap progression between the terms in the Fibonacci sequence encourages the team to deliver carefully considered estimates. Estimates of 1, 2 or 3 imply similar efforts (1 being trivial), but if the team estimates an 8 or 13 (or higher), the impact on both delivery and budget can be significant. The value of using story points is that the team can reuse them by comparing similar work from previous sprints, but it should be recognized that estimates are relative to the team. For example, an estimate of 5 for one team could be a 2 for another having senior developers and higher skills.
Every team should have a product owner, although in many instances a product owner could work with more than one team.[24] The product owner is responsible for maximizing the value of the product. The product owner gathers input and takes feedback from, and is lobbied by, many people, but ultimately makes the call on what gets built.
The product backlog:
- Captures requests to modify a product—including new features, replacing old features, removing features, and fixing issues
- Ensures the development team has work that maximizes business benefit to the product owner
Typically, the product owner and the scrum team work together to develop the breakdown of work; this becomes the product backlog, which evolves as new information surfaces about the product and about its customers, and so later sprints may address new work.
Management[edit]
A product backlog, in its simplest form, is merely a list of items to work on. Having well-established rules about how work is added, removed and ordered helps the whole team make better decisions about how to change the product.[42]
The product owner prioritizes product backlog items based on which are needed soonest. The team then chooses which items they can complete in the coming sprint. On the scrum board, the team moves items from the product backlog to the sprint backlog, which is the list of items they will build. Conceptually, it is ideal for the team to only select what they think they can accomplish from the top of the list, but it is not unusual to see in practice that teams are able to take lower-priority items from the list along with the top ones selected. This normally happens because there is time left within the sprint to accommodate more work. Items at the top of the backlog, the items to work on first, should be broken down into stories that are suitable for the development team to work on. The further down the backlog goes, the less refined the items should be. As Schwaber and Beedle put it 'The lower the priority, the less detail until you can barely make out the backlog item.'[2]
As the team works through the backlog, it must be assumed that change happens outside their environment—the team can learn about new market opportunities to take advantage of, competitor threats that arise, and feedback from customers that can change the way the product was meant to work. All of these new ideas tend to trigger the team to adapt the backlog to incorporate new knowledge. This is part of the fundamental mindset of an agile team. The world changes, the backlog is never finished.[26]
Sprint backlog[edit]
A scrum task board
The sprint backlog is the list of work the development team must address during the next sprint.[43] The list is derived by the scrum team progressively selecting product backlog items in priority order from the top of the product backlog until they feel they have enough work to fill the sprint. The development team should keep in mind its past performance assessing its capacity for the new-sprint, and use this as a guideline of how much 'effort' they can complete.
The product backlog items may be broken down into tasks by the development team.[43] Tasks on the sprint backlog are never assigned (or pushed) to team members by someone else; rather team members sign up for (or pull) tasks as needed according to the backlog priority and their own skills and capacity. This promotes self-organization of the development team and developer buy-in.
The sprint backlog is the property of the development team, and all included estimates are provided by the development team. Often an accompanying task board is used to see and change the state of the tasks of the current sprint, like to do, in progress and done.
Once a sprint backlog is committed, no additional work can be added to the sprint backlog except by the team. Once a sprint has been delivered, the product backlog is analyzed and reprioritized if necessary, and the next set of functionality is selected for the next sprint.
Increment[edit]
The increment is the potentially releasable output of the sprint that meets the sprint goal. It is formed from all the completed sprint backlog items, integrated with the work of all previous sprints. The increment must be complete, according to the scrum team's definition of done (DoD), fully functioning, and in a usable condition regardless of whether the product owner decides to actually deploy and use it.
Extensions[edit]
The following artifacts and techniques can be used to help people use Scrum.[16]
Sprint burndown chart[edit]
A sample burndown chart for a completed sprint, showing remaining effort at the end of each day.
The sprint burndown chart is a publicly displayed chart showing remaining work in the sprint backlog.[44] Updated every day, it gives a simple view of the sprint progress. It also provides quick visualizations for reference. The horizontal axis of the sprint burndown chart shows the days in a sprint, while the vertical axis shows the amount of work remaining each day (typically representing the estimate of hours of work remaining).
During sprint planning, the ideal burndown chart is plotted. Then, during the sprint, each member picks up tasks from the sprint backlog and works on them. At the end of the day, they update the remaining hours for tasks to be completed. In such a way, the actual burndown chart is updated day by day.
It should not be confused with an earned value chart.
Release burn-up chart[edit]
A sample burn-up chart for a release, showing scope completed each sprint
The release burn-up chart is a way for the team to provide visibility and track progress toward a release. Updated at the end of each sprint, it shows progress toward delivering a forecast scope. The horizontal axis of the release burn-up chart shows the sprints in a release, while the vertical axis shows the amount of work completed at the end of each sprint (typically representing cumulative story points of work completed). Progress is plotted as a line that grows up to meet a horizontal line that represents the forecast scope; often shown with a forecast, based on progress to date, that indicates how much scope might be completed by a given release date or how many sprints it will take to complete the given scope.
The release burn-up chart makes it easy to see how much work has been completed, how much work has been added or removed (if the horizontal scope line moves), and how much work is left to be done.
Definition of ready (DoR)[edit]
The start criteria to determine whether the specifications and inputs are set enough to start the work item, i.e. a user story.
Definition of done (DoD)[edit]
The exit-criteria to determine whether a product backlog item is complete. In many cases, the DoD requires that all regression tests be successful. The definition of done may vary from one scrum team to another but must be consistent within one team.[45]
Velocity[edit]
The total effort a team is capable of in a sprint. The number is derived by evaluating the work (typically in user story points) completed in the last sprint. The collection of historical velocity data is a guideline for assisting the team in understanding how much work they can likely achieve in a future sprint.
Spike[edit]
A time-boxed period used to research a concept or create a simple prototype. Spikes can either be planned to take place in between sprints or, for larger teams, a spike might be accepted as one of many sprint delivery objectives. Spikes are often introduced before the delivery of large or complex product backlog items in order to secure budget, expand knowledge, or produce a proof of concept. The duration and objective(s) of a spike is agreed between product owner and development team before the start. Unlike sprint commitments, spikes may or may not deliver tangible, shippable, valuable functionality. For example, the objective of a spike might be to successfully reach a decision on a course of action. The spike is over when the time is up, not necessarily when the objective has been delivered.[46]
Tracer bullet[edit]
Also called a drone spike, a tracer bullet is a spike with the current architecture, current technology set, current set of best practices that result in production quality code. It might just be a very narrow implementation of the functionality but is not throwaway code. It is of production quality, and the rest of the iterations can build on this code. The name has military origins as ammunition that makes the path of the bullet visible, allowing for corrections. Often these implementations are a 'quick shot' through all layers of an application, such as connecting a single form's input field to the back-end, to prove the layers connect as expected.[47]
Limitations[edit]
The benefits of Scrum may be more difficult to achieve when:[48][49]
- Teams whose members are geographically dispersed or part-time: In Scrum, developers should have close and ongoing interaction, ideally working together in the same space most of the time. While recent improvements in technology have reduced the impact of these barriers (e.g., being able to collaborate on a digital whiteboard), the Agile manifesto asserts that the best communication is face to face.[50]
- Teams whose members have very specialized skills: In Scrum, developers should have T-shaped skills, allowing them to work on tasks outside of their specialization. This can be encouraged by good Scrum leadership. While team members with very specific skills can and do contribute well, they should be encouraged to learn more about and collaborate with other disciplines.
- Products with many external dependencies: In Scrum, dividing product development into short sprints requires careful planning; external dependencies, such as user acceptance testing or coordination with other teams, can lead to delays and the failure of individual sprints.
- Products that are mature or legacy or with regulated quality control: In Scrum, product increments should be fully developed and tested in a single sprint; products that need large amounts of regression testing or safety testing (e.g., medical devices or vehicle control) for each release are less suited to short sprints than to longer waterfall releases.
From a business perspective, Scrum has many virtues, one of which is that it is designed to yield the best business solutions. However, the efficiency by which it does so in any given organization can vary widely and is largely dependent on the ability of the organization to adhere to the implementation guidelines. Every company has its own distinct organizational structure, culture, and set of business practices, and some are more naturally amenable to this methodology than others.
Tools for implementation[edit]
Like other agile methods, effective adoption of Scrum can be supported through a wide range of tools.
Many companies use universal tools, such as spreadsheets to build and maintain artifacts such as the sprint backlog. There are also open-source and proprietary software packages for Scrum—which are either dedicated to product development using the Scrum framework or support multiple product development approaches including Scrum.
Other organizations implement Scrum without software tools and maintain their artifacts in hard-copy forms such as paper, whiteboards, and sticky notes.[51]
Scrum values[edit]
Scrum is a feedback-driven empirical approach which is, like all empirical process control, underpinned by the three pillars of transparency, inspection, and adaptation. All work within the Scrum framework should be visible to those responsible for the outcome: the process, the workflow, progress, etc. In order to make these things visible, scrum teams need to frequently inspect the product being developed and how well the team is working. With frequent inspection, the team can spot when their work deviates outside of acceptable limits and adapt their process or the product under development.[23]
These three pillars require trust and openness in the team, which the following five values of Scrum enable:[16]
- Commitment: Team members individually commit to achieving their team goals, each and every sprint.
- Courage: Team members know they have the courage to work through conflict and challenges together so that they can do the right thing.
- Focus: Team members focus exclusively on their team goals and the sprint backlog; there should be no work done other than through their backlog.
- Openness: Team members and their stakeholders agree to be transparent about their work and any challenges they face.
- Respect: Team members respect each other to be technically capable and to work with good intent.
Adaptations[edit]
The hybridization of Scrum with other software development methodologies is common as Scrum does not cover the whole product development lifecycle; therefore, organizations find the need to add in additional processes to create a more comprehensive implementation. For example, at the start of product development, organizations commonly add process guidance on the business case, requirements gathering and prioritization, initial high-level design, and budget and schedule forecasting.[52]
Various authors and communities of people who use Scrum have also suggested more detailed techniques for how to apply or adapt Scrum to particular problems or organizations. Many refer to these methodological techniques as 'patterns' - by analogy with design patterns in architecture and software.[53][54] Such patterns have extended Scrum outside of the software development domain into Manufacturing,[55] Finance and Human Resources.
Scrumban[edit]
Scrumban is a software production model based on Scrum and Kanban. Scrumban is especially suited for product maintenance with frequent and unexpected work items, such as production defects or programming errors. In such cases the time-limited sprints of the Scrum framework may be perceived to be of less benefit, although Scrum's daily events and other practices can still be applied, depending on the team and the situation at hand. Visualization of the work stages and limitations for simultaneous unfinished work and defects are familiar from the Kanban model. Using these methods, the team's workflow is directed in a way that allows for minimum completion time for each work item or programming error, and on the other hand ensures each team member is constantly employed.[56]
To illustrate each stage of work, teams working in the same space often use post-it notes or a large whiteboard.[57] In the case of decentralized teams, stage-illustration software such as Assembla, JIRA or Agilo.
The major differences between Scrum and Kanban is that in Scrum work is divided into sprints that last a fixed amount of time, whereas in Kanban the flow of work is continuous. This is visible in work stage tables, which in Scrum are emptied after each sprint, whereas in Kanban all tasks are marked on the same table. Scrum focuses on teams with multifaceted know-how, whereas Kanban makes specialized, functional teams possible.[56]
Scrum of scrums[edit]
The scrum of scrums is a technique to operate Scrum at scale, for multiple teams working on the same product, allowing them to discuss progress on their interdependencies, focusing on how to coordinate delivering software,[58] especially on areas of overlap and integration. Depending on the cadence (timing) of the scrum of scrums, the relevant daily scrum for each scrum team ends by designating one member as an ambassador to participate in the scrum of scrums with ambassadors from other teams. Depending on the context, the ambassadors may be technical contributors or each team's scrum master.[58]
Rather than simply a progress update, the scrum of scrums should focus on how teams are collectively working to resolve, mitigate, or accept any risks, impediments, dependencies, and assumptions (RIDAs) that have been identified. The scrum of scrums tracks these RIDAs via a backlog of its own, such as a risk board (sometimes known as a ROAM board after the initials of resolved, owned, accepted, and mitigated),[59] which typically leads to greater coordination and collaboration between teams.[58]
This should run similar to a daily scrum, with each ambassador answering the following four questions:[60]
- What risks, impediments, dependencies, or assumptions has your team resolved since we last met?
- What risks, impediments, dependencies, or assumptions will your team resolve before we meet again?
- Are there any new risks, impediments, dependencies, or assumptions slowing your team down or getting in their way?
- Are you about to introduce a new risk, impediment, dependency, or assumption that will get in another team's way?
As Jeff Sutherland commented,[58]
Since I originally defined the Scrum of Scrums (Ken Schwaber was at IDX working with me), I can definitively say the Scrum of Scrums is not a 'meta Scrum'. The Scrum of Scrums as I have used it is responsible for delivering the working software of all teams to the Definition of Done at the end of the sprint, or for releases during the sprint. PatientKeeper delivered to production four times per Sprint. Ancestry.com delivers to production 220 times per two-week Sprint. Hubspot delivers live software 100-300 times a day. The Scrum of Scrums Master is held accountable for making this work. So the Scrum of Scrums is an operational delivery mechanism.
Large-scale Scrum[edit]
Large-scale Scrum (LeSS) is a product development framework that extends Scrum with scaling rules and guidelines without losing the original purposes of Scrum.
There are two levels to the framework: the first LeSS level is designed for up to eight teams; the second level, known as 'LeSS Huge', introduces additional scaling elements for development with up to hundreds of developers. 'Scaling Scrum starts with understanding and being able to adopt standard real one-team Scrum. Large-scale Scrum requires examining the purpose of single-team Scrum elements and figuring out how to reach the same purpose while staying within the constraints of the standard Scrum rules.'[61]
Bas Vodde and Craig Larman evolved the LeSS framework from their experiences working with large-scale product development, especially in the telecoms and finance industries. It evolved by taking Scrum and trying many different experiments to discover what works. In 2013, the experiments were solidified into the LeSS framework rules.[62] The intention of LeSS is to 'descale' organization complexity, dissolving unnecessary complex organizational solutions, and solving them in simpler ways. Less roles, less management, less organizational structures.[63]
See also[edit]
References[edit]
- ^'Lessons learned: Using Scrum in non-technical teams'. Agile Alliance. Retrieved April 8, 2019.
- ^ abcdeSchwaber, Ken (February 1, 2004). Agile Project Management with Scrum. Microsoft Press. ISBN978-0-7356-1993-7.
- ^Daily Scrum Meeting, Mountain Goat Software, retrieved July 26, 2017
- ^'What is Scrum?'. What is Scrum? An Agile Framework for Completing Complex Projects - Scrum Alliance. Scrum Alliance. Retrieved February 24, 2016.
- ^Verheyen, Gunther (March 21, 2013). 'Scrum: Framework, not methodology'. Gunther Verheyen. Gunther Verheyen. Retrieved February 24, 2016.
- ^J. Henry and S. Henry. Quantitative assessment of the software maintenance process and requirements volatility. In Proc. of the ACM Conference on Computer Science, pages 346–351, 1993.
- ^'Should 'SCRUM' be written in all caps?'. stackoverflow.com. Retrieved January 10, 2017.
- ^Schwaber, Ken. 'Scrum.org Ken Schwaber'.Cite journal requires
|journal=
(help) - ^Schwaber, Ken (2004). 'SCRUM Development Process'(PDF). Advanced Development Methods.
- ^Johnson, Hillary Louise (January 13, 2011). 'ScrumMaster vs scrum master: What do you think?'. agilelearninglabs.com. Retrieved May 10, 2017.
- ^ abcTakeuchi, Hirotaka; Nonaka, Ikujiro (January 1, 1986). 'The New New Product Development Game'. Harvard Business Review. Retrieved June 9, 2010.
Moving the Scrum Downfield
- ^The Knowledge Creating Company. Oxford University Press. 1995. p. 3. ISBN9780199762330. Retrieved March 12, 2013.
- ^'Scrum'. Oxford Dictionaries. Oxford University Press.
- ^ abSutherland, Jeff (October 2004). 'Agile Development: Lessons learned from the first Scrum'. Archived from the original(PDF) on November 22, 2017. Retrieved September 26, 2008.
- ^Sutherland, Jeffrey Victor; Schwaber, Ken (1995). Business object design and implementation: OOPSLA '95 workshop proceedings. The University of Michigan. p. 118. ISBN978-3-540-76096-2.
- ^ abcdefghijKen Schwaber; Jeff Sutherland. 'The Scrum Guide'(PDF). Scrum.org. Retrieved October 27, 2017.
- ^Schwaber, Ken; Beedle, Mike (2002). Agile software development with Scrum. Prentice Hall. ISBN978-0-13-067634-4.
- ^Maximini, Dominik (January 8, 2015). The Scrum Culture: Introducing Agile Methods in Organizations. Management for Professionals. Cham: Springer (published 2015). p. 26. ISBN9783319118277. Retrieved August 25, 2016.
Ken Schwaber and Jeff Sutherland presented Scrum for the first time at the OOPSLA conference in Austin, Texas, in 1995. [..] In 2001, the first book about Scrum was published. [..] One year later (2002), Ken founded the Scrum Alliance, aiming at providing worldwide Scrum training and certification.
- ^Partogi, Joshua (July 7, 2013). 'Certified Scrum Master vs Professional Scrum Master'. Lean Agile Institute. Retrieved May 10, 2017.
- ^ abRad, Nader K.; Turley, Frank (2018). Agile Scrum Foundation Courseware, Second Edition. 's-Hertogenbosch, Netherlands: Van Haren. p. 26. ISBN9789401802796.
- ^ abMcGreal, Don; Jocham, Ralph (June 4, 2018). The Professional Product Owner: Leveraging Scrum as a Competitive Advantage. Addison-Wesley Professional. ISBN9780134686653.
- ^Rubin, Kenneth (2013), Essential Scrum. A Practical Guide to the Most Popular Agile Process, Addison-Wesley, p. 173, ISBN978-0-13-704329-3
- ^ abcdMorris, David (2017). Scrum: an ideal framework for agile projects. In Easy Steps. pp. 178–179. ISBN9781840787313. OCLC951453155.
- ^ abcCohn, Mike. Succeeding with Agile: Software Development Using Scrum. Upper Saddle River, NJ: Addison-Wesley, 2010.
- ^'The Role of the Product Owner'. Scrum Alliance. Retrieved May 26, 2018.
- ^ abPichler, Roman. Agile Product Management with Scrum: Creating Products that Customers Love. Upper Saddle River, NJ: Addison-Wesley, 2010.[need quotation to verify]
- ^Ambler, Scott. 'The Product Owner Role: A Stakeholder Proxy for Agile Teams'. agilemodeling.com. Retrieved July 22, 2016.
[..] in practice there proves to be two critical aspects to this role: first as a stakeholder proxy within the development team and second as a project team representative to the overall stakeholder community as a whole.
- ^'The Product Owner Role'. Scrum Master Test Prep. Retrieved February 3, 2017.
- ^Carroll, N, O’Connor, M. and Edison, H. (2018). The Identification and Classification of Impediments to Software Flow, The Americas Conference on Information Systems (AMCIS 2018), 16-18 August, New Orleans, Louisiana, USA.
- ^Leybourn, E. (2013). Directing the Agile Organisation: A Lean Approach to Business Management. London: IT Governance Publishing: 117–120.
- ^'Core Scrum'. Scrum Alliance. Retrieved January 25, 2015.
- ^ abDrongelen, Mike van; Dennis, Adam; Garabedian, Richard; Gonzalez, Alberto; Krishnaswamy, Aravind (2017). Lean Mobile App Development: Apply Lean startup methodologies to develop successful iOS and Android apps. Birmingham, UK: Packt Publishing Ltd. p. 43. ISBN9781786467041.
- ^Cobb, Charles G. (2015). The Project Manager's Guide to Mastering Agile: Principles and Practices for an Adaptive Approach. Hoboken, NJ: John Wiley & Sons. p. 37. ISBN9781118991046.
- ^ abcPete Deemer; Gabrielle Benefield; Craig Larman; Bas Vodde (December 17, 2012). 'The Scrum Primer: A Lightweight Guide to the Theory and Practice of Scrum (Version 2.0)'. InfoQ.
- ^Gangji, Arif; Hartman, Bob (2015). 'Agile SCRUM For Denver Web Development'. Neon Rain Interactive. Retrieved September 25, 2015.
- ^Little, Joe (January 17, 2011). 'Impediment Management'. Agile Consortium.Cite journal requires
|journal=
(help) - ^ abFlewelling, Paul (2018). The Agile Developer's Handbook: Get more value from your software development: get the best out of the Agile methodology. Birmingham, UK: Packt Publishing Ltd. p. 91. ISBN9781787280205.
- ^McKenna, Dave (2016). The Art of Scrum: How Scrum Masters Bind Dev Teams and Unleash Agility. Aliquippa, PA: CA Press. p. 126. ISBN9781484222768.
- ^Cho, L (2009). Adopting an Agile Culture A User Experience Team's Journey. Agile Conference. pp. 416–421. doi:10.1109/AGILE.2009.76. ISBN978-0-7695-3768-9.
- ^Sedano, Todd; Ralph, Paul; Péraire, Cécile. 'The Product Backlog'. IEEE.
- ^Higgins, Tony (March 31, 2009). 'Authoring Requirements in an Agile World'. BA Times.
- ^'The product backlog: your ultimate to-do list'. Atlassian. Retrieved July 20, 2016.
- ^ abRuss J. Martinelli; Dragan Z. Milosevic (January 5, 2016). Project Management ToolBox: Tools and Techniques for the Practicing Project Manager. Wiley. p. 304. ISBN978-1-118-97320-2.
- ^Charles G. Cobb (January 27, 2015). The Project Manager's Guide to Mastering Agile: Principles and Practices for an Adaptive Approach. John Wiley & Sons. p. 378. ISBN978-1-118-99104-6.
- ^Ken Schwaber, Agile Project Management with Scrum, p.55
- ^'Create a Spike Solution'. Extreme Programming.
- ^Sterling, Chris (October 22, 2007). 'Research, Spikes, Tracer Bullets, Oh My!'. Getting Agile. Retrieved October 23, 2016.
- ^Turk, Dan; France, Robert; Rumpe, Bernhard (2014) [2002]. 'Limitations of Agile Software Processes'. Proceedings of the Third International Conference on Extreme Programming and Flexible Processes in Software Engineering: 43–46. arXiv:1409.6600v1.
- ^'Issues and Challenges in Scrum Implementation'(PDF). International Journal of Scientific & Engineering Research. 3 (8). August 2012. Retrieved December 10, 2015.
- ^Kent Beck; James Grenning; Robert C. Martin; Mike Beedle; Jim Highsmith; Steve Mellor; Arie van Bennekum; Andrew Hunt; Ken Schwaber; Alistair Cockburn; Ron Jeffries; Jeff Sutherland; Ward Cunningham; Jon Kern; Dave Thomas; Martin Fowler; Brian Marick (2001). 'Principles behind the Agile Manifesto'. Agile Alliance. Retrieved August 7, 2017.
- ^Dubakov, Michael (2008). 'Agile Tools. The Good, the Bad and the Ugly'(PDF). Retrieved August 30, 2010.
- ^Hron, M.; Obwegeser, N. (January 2018). 'Scrum in practice: an overview of Scrum adaptations'(PDF). Proceedings of the 2018 51st Hawaii International Conference on System Sciences (HICSS), January 3-6, 2018.
- ^Bjørnvig, Gertrud; Coplien, Jim (June 21, 2008). 'Scrum as Organizational Patterns'. Gertrude & Cope.
- ^'Scrum Pattern Community'. ScrumPLoP.org. Retrieved July 22, 2016.
- ^'WIKISPEED – Applying Agile software principles and practices for fast automotive development'. Agile Business Management Consortium. December 3, 2013. Retrieved September 11, 2015.
- ^ abKniberg, Henrik; Skarin, Mattias (December 21, 2009). 'Kanban and Scrum - Making the most of both'(PDF). InfoQ. Retrieved July 22, 2016.
- ^Ladas, Corey (October 27, 2007). 'scrum-ban'. Lean Software Engineering. Retrieved September 13, 2012.
- ^ abcd'Scrum of Scrums'. Agile Alliance. December 17, 2015.
- ^'Risk Management – How to Stop Risks from Screwing Up Your Projects!'. Kelly Waters.
- ^'Scrum of Scrums'. Scrum Master Test Prep. Retrieved May 29, 2015.
- ^Larman; scrumyear=2013. 'Scaling Agile Development (Crosstalk journal, November / December 2013)'(PDF).
- ^'Large-Scale Scrum (LeSS)'. 2014.
- ^Grgic (2015). 'Descaling organisation with LeSS (Blog)'.
Further reading[edit]
- Vacaniti, Daniel (February 2018). 'The Kanban Guide for Scrum Teams'(PDF). scrum.org. Retrieved March 12, 2018.
- Sutherland, Jeff; Schwaber, Ken (2013). 'Scrum Guides'. ScrumGuides.org. Retrieved July 26, 2017.
- Verheyen, Gunther (2013). Scrum - A Pocket Guide (A Smart Travel Companion)ISBN978-9087537203.
- Münch, Jürgen; Armbrust, Ove; Soto, Martín; Kowalczyk, Martin (2012). Software Process Definition and Management. ISBN978-3-642-24291-5.
- Deemer, Pete; Benefield, Gabrielle; Larman, Craig; Vodde, Bas (2009). 'The Scrum Primer'. Retrieved June 1, 2009.
- Janoff, N.S.; Rising, L. (2000). 'The Scrum Software Development Process for Small Teams'(PDF). Retrieved February 26, 2015.
External links[edit]
Wikimedia Commons has media related to Scrum (development). |
- Scaled Scrum by Scrum.org
- A Scrum Process Description by the Eclipse Process Framework (EPF) Project
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Scrum_(software_development)&oldid=917595505'