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Software development process

January 20, 2023

In software engineering, a software development process is a process of dividing software development work into smaller, parallel, or sequential steps or sub-processes to improve design and/or product management. It is also known as a software development life cycle (SDLC). The methodology may include the pre-definition of specific deliverables and artifacts that are created and completed by a project team to develop or maintain an application.[1]

Most modern development processes can be vaguely described as agile. Other methodologies include waterfall, prototyping, iterative and incremental development, spiral development, rapid application development, and extreme programming.

A life-cycle "model" is sometimes considered a more general term for a category of methodologies and a software development "process" a more specific term to refer to a specific process chosen by a specific organization.[citation needed] For example, there are many specific software development processes that fit the spiral life-cycle model. The field is often considered a subset of the systems development life cycle.

History

The software development methodology (also known as SDM) framework didn't emerge until the 1960s. According to Elliott (2004), the systems development life cycle (SDLC) can be considered to be the oldest formalized methodology framework for building information systems. The main idea of the SDLC has been "to pursue the development of information systems in a very deliberate, structured and methodical way, requiring each stage of the life cycle––from the inception of the idea to delivery of the final system––to be carried out rigidly and sequentially"[2] within the context of the framework being applied. The main target of this methodology framework in the 1960s was "to develop large scale functional business systems in an age of large scale business conglomerates. Information systems activities revolved around heavy data processing and number crunching routines".[2]

Methodologies, processes, and frameworks range from specific prescriptive steps that can be used directly by an organization in day-to-day work, to flexible frameworks that an organization uses to generate a custom set of steps tailored to the needs of a specific project or group. In some cases, a "sponsor" or "maintenance" organization distributes an official set of documents that describe the process. Specific examples include:

1970s
1980s
1990s
2000s

2010s

It is notable that since DSDM in 1994, all of the methodologies on the above list except RUP have been agile methodologies - yet many organizations, especially governments, still use pre-agile processes (often waterfall or similar). Software process and software quality are closely interrelated; some unexpected facets and effects have been observed in practice [3]

Among these, another software development process has been established in open source. The adoption of these best practices known and established processes within the confines of a company is called inner source.

Prototyping

Software prototyping is about creating prototypes, i.e. incomplete versions of the software program being developed.

The basic principles are:[1]

  • Prototyping is not a standalone, complete development methodology, but rather an approach to try out particular features in the context of a full methodology (such as incremental, spiral, or rapid application development (RAD)).
  • Attempts to reduce inherent project risk by breaking a project into smaller segments and providing more ease-of-change during the development process.
  • The client is involved throughout the development process, which increases the likelihood of client acceptance of the final implementation.
  • While some prototypes are developed with the expectation that they will be discarded, it is possible in some cases to evolve from prototype to working system.

A basic understanding of the fundamental business problem is necessary to avoid solving the wrong problems, but this is true for all software methodologies.

Methodologies

Agile development

Main article: Agile software development

"Agile software development" refers to a group of software development frameworks based on iterative development, where requirements and solutions evolve via collaboration between self-organizing cross-functional teams. The term was coined in the year 2001 when the Agile Manifesto was formulated.

Agile software development uses iterative development as a basis but advocates a lighter and more people-centric viewpoint than traditional approaches. Agile processes fundamentally incorporate iteration and the continuous feedback that it provides to successively refine and deliver a software system.

The Agile model also includes the following software development processes:[4]

Continuous integration

Main article: Continuous integration

Continuous integration is the practice of merging all developer working copies to a shared mainline several times a day.[5] Grady Booch first named and proposed CI in his 1991 method,[6] although he did not advocate integrating several times a day. Extreme programming (XP) adopted the concept of CI and did advocate integrating more than once per day – perhaps as many as tens of times per day.

Incremental development

Main article: Iterative and incremental development

Various methods are acceptable for combining linear and iterative systems development methodologies, with the primary objective of each being to reduce inherent project risk by breaking a project into smaller segments and providing more ease-of-change during the development process.

There are three main variants of incremental development:[1]

  1. A series of mini-Waterfalls are performed, where all phases of the Waterfall are completed for a small part of a system, before proceeding to the next increment, or
  2. Overall requirements are defined before proceeding to evolutionary, mini-Waterfall development of individual increments of a system, or
  3. The initial software concept, requirements analysis, and design of architecture and system core are defined via Waterfall, followed by incremental implementation, which culminates in installing the final version, a working system.

Rapid application development

Main article: Rapid application development
 
Rapid Application Development (RAD) Model

Rapid application development (RAD) is a software development methodology, which favors iterative development and the rapid construction of prototypes instead of large amounts of up-front planning. The "planning" of software developed using RAD is interleaved with writing the software itself. The lack of extensive pre-planning generally allows software to be written much faster, and makes it easier to change requirements.

The rapid development process starts with the development of preliminary data models and business process models using structured techniques. In the next stage, requirements are verified using prototyping, eventually to refine the data and process models. These stages are repeated iteratively; further development results in "a combined business requirements and technical design statement to be used for constructing new systems".[7]

The term was first used to describe a software development process introduced by James Martin in 1991. According to Whitten (2003), it is a merger of various structured techniques, especially data-driven information technology engineering, with prototyping techniques to accelerate software systems development.[7]

The basic principles of rapid application development are:[1]

  • Key objective is for fast development and delivery of a high quality system at a relatively low investment cost.
  • Attempts to reduce inherent project risk by breaking a project into smaller segments and providing more ease-of-change during the development process.
  • Aims to produce high quality systems quickly, primarily via iterative Prototyping (at any stage of development), active user involvement, and computerized development tools. These tools may include Graphical User Interface (GUI) builders, Computer Aided Software Engineering (CASE) tools, Database Management Systems (DBMS), fourth-generation programming languages, code generators, and object-oriented techniques.
  • Key emphasis is on fulfilling the business need, while technological or engineering excellence is of lesser importance.
  • Project control involves prioritizing development and defining delivery deadlines or “timeboxes”. If the project starts to slip, emphasis is on reducing requirements to fit the timebox, not in increasing the deadline.
  • Generally includes joint application design (JAD), where users are intensely involved in system design, via consensus building in either structured workshops, or electronically facilitated interaction.
  • Active user involvement is imperative.
  • Iteratively produces production software, as opposed to a throwaway prototype.
  • Produces documentation necessary to facilitate future development and maintenance.
  • Standard systems analysis and design methods can be fitted into this framework.

Waterfall development

Main article: Waterfall model
 
The activities of the software development process represented in the waterfall model. There are several other models to represent this process.

The waterfall model is a sequential development approach, in which development is seen as flowing steadily downwards (like a waterfall) through several phases, typically:

The first formal description of the method is often cited as an article published by Winston W. Royce[8] in 1970, although Royce did not use the term "waterfall" in this article. Royce presented this model as an example of a flawed, non-working model.[9]

The basic principles are:[1]

  • The Project is divided into sequential phases, with some overlap and splash back acceptable between phases.
  • Emphasis is on planning, time schedules, target dates, budgets, and implementation of an entire system at one time.
  • Tight control is maintained over the life of the project via extensive written documentation, formal reviews, and approval/signoff by the user and information technology management occurring at the end of most phases before beginning the next phase. Written documentation is an explicit deliverable of each phase.

The waterfall model is a traditional engineering approach applied to software engineering. A strict waterfall approach discourages revisiting and revising any prior phase once it is complete.[according to whom?] This "inflexibility" in a pure waterfall model has been a source of criticism by supporters of other more "flexible" models. It has been widely blamed for several large-scale government projects running over budget, over time and sometimes failing to deliver on requirements due to the Big Design Up Front approach.[according to whom?] Except when contractually required, the waterfall model has been largely superseded by more flexible and versatile methodologies developed specifically for software development.[according to whom?] See Criticism of Waterfall model.

Spiral development

 
Spiral model (Boehm, 1988)
Main article: Spiral model

In 1988, Barry Boehm published a formal software system development "spiral model," which combines some key aspects of the waterfall model and rapid prototyping methodologies, in an effort to combine advantages of top-down and bottom-up concepts. It provided emphasis in a key area many felt had been neglected by other methodologies: deliberate iterative risk analysis, particularly suited to large-scale complex systems.

The basic principles are:[1]

  • Focus is on risk assessment and on minimizing project risk by breaking a project into smaller segments and providing more ease-of-change during the development process, as well as providing the opportunity to evaluate risks and weigh consideration of project continuation throughout the life cycle.
  • "Each cycle involves a progression through the same sequence of steps, for each part of the product and for each of its levels of elaboration, from an overall concept-of-operation document down to the coding of each individual program."[10]
  • Each trip around the spiral traverses four basic quadrants: (1) determine objectives, alternatives, and constraints of the iteration, and (2) evaluate alternatives; Identify and resolve risks; (3) develop and verify deliverables from the iteration; and (4) plan the next iteration.[11]
  • Begin each cycle with an identification of stakeholders and their "win conditions", and end each cycle with review and commitment.[12]

Shape Up

Shape Up is a software development approach introduced by Basecamp in 2018. It is a set of principles and techniques that Basecamp developed internally to overcome the problem of projects dragging on with no clear end. Its primary target audience is remote teams. Shape Up has no estimation and velocity tracking, backlogs, or sprints, unlike Waterfall, Agile, or Scrum. Instead, those concepts are replaced with appetite, betting, and cycles. As of 2022, besides Basecamp, notable organizations that have adopted Shape Up include UserVoice and Block.[13][14]

Cycles

Through trials and errors, Basecamp found that the ideal cycle length is 6 weeks. This 6 week period is long enough to build a meaningful feature and still short enough to induce a sense of urgency.

Shaping

Shaping is the process of preparing work before being handed over to designers and engineers. Shaped work spells out the solution's main UI elements, identifies rabbit holes, and outlines clear scope boundaries. It is meant to be rough and to leave finer details for builders (designers and engineers) to solve, allowing the builders to exercise their creativity and make trade-offs.[15] Shaped work is documented in the form of a pitch using an online document solution that supports commenting, allowing team members to contribute technical information asynchronously. Such comments are crucial for uncovering hidden surprises that may derail the project.

Before a cycle begins, stakeholders hold a betting table, where pitches are reviewed. For each pitch, a decision is made to either bet on it or drop it.[16]

Appetite

The way Shape Up determines how much time is allocated to a project is diametrically opposed to other methodologies. Shape Up starts with an appetite (for example, 6 weeks) and ends with a solution design that can be delivered within this constraint. The appetite becomes a hard deadline for the project's builders.[17]

Building

Shape Up is a two-track system where shapers and builders work in parallel. Work that is being shaped in the current cycle may be given to designers and engineers to build in a future cycle.

Recognizing the technical uncertainties that come with building, progress is tracked using a chart that visualizes the metaphor of the hill, aptly named the hill chart. The uphill phase is where builders are still working out their approach, while the downhill is where unknowns have been eliminated. Builders proactively and asynchronously self-report progress using an interactive online hill chart on Basecamp or Jira, shifting focus from done or not-done statuses to unknown or solved problems. The use of hill chart replaces the process of reporting linear statuses in scrum or Kanban standup.[18][19]

Advanced methodologies

Other high-level software project methodologies include:

  • Behavior-driven development and business process management.[20]
  • Chaos model - The main rule always resolve the most important issue first.
  • Incremental funding methodology - an iterative approach
  • Lightweight methodology - a general term for methods that only have a few rules and practices
  • Structured systems analysis and design method - a specific version of waterfall
  • Slow programming, as part of the larger Slow Movement, emphasizes careful and gradual work without (or minimal) time pressures. Slow programming aims to avoid bugs and overly quick release schedules.
  • V-Model (software development) - an extension of the waterfall model
  • Unified Process (UP) is an iterative software development methodology framework, based on Unified Modeling Language (UML). UP organizes the development of software into four phases, each consisting of one or more executable iterations of the software at that stage of development: inception, elaboration, construction, and guidelines. Many tools and products exist to facilitate UP implementation. One of the more popular versions of UP is the Rational Unified Process (RUP).
  • Big Bang methodology - an approach for small or undefined projects, generally consisting of little to no planning with high risk.

Process meta-models

Some "process models" are abstract descriptions for evaluating, comparing, and improving the specific process adopted by an organization.

  • ISO/IEC 12207 is the international standard describing the method to select, implement, and monitor the life cycle for software.
  • The Capability Maturity Model Integration (CMMI) is one of the leading models and is based on best practices. Independent assessments grade organizations on how well they follow their defined processes, not on the quality of those processes or the software produced. CMMI has replaced CMM.
  • ISO 9000 describes standards for a formally organized process to manufacture a product and the methods of managing and monitoring progress. Although the standard was originally created for the manufacturing sector, ISO 9000 standards have been applied to software development as well. Like CMMI, certification with ISO 9000 does not guarantee the quality of the end result, only that formalized business processes have been followed.
  • ISO/IEC 15504 Information technology—Process assessment is also known as Software Process Improvement Capability Determination (SPICE), is a "framework for the assessment of software processes". This standard is aimed at setting out a clear model for process comparison. SPICE is used much like CMMI. It models processes to manage, control, guide and monitors software development. This model is then used to measure what a development organization or project team actually does during software development. This information is analyzed to identify weaknesses and drive improvement. It also identifies strengths that can be continued or integrated into common practice for that organization or team.
  • ISO/IEC 24744 Software Engineering—Metamodel for Development Methodologies, is a power type-based metamodel for software development methodologies.
  • SPEM 2.0 by the Object Management Group.
  • Soft systems methodology - a general method for improving management processes.
  • Method engineering - a general method for improving information system processes.
Further information: Process patterns

In practice

 
The three basic approaches applied to software development methodology frameworks.

A variety of such frameworks have evolved over the years, each with its own recognized strengths and weaknesses. One software development methodology framework is not necessarily suitable for use by all projects. Each of the available methodology frameworks is best suited to specific kinds of projects, based on various technical, organizational, project, and team considerations.[1]

Software development organizations implement process methodologies to ease the process of development. Sometimes, contractors may require methodologies employed, an example is the U.S. defense industry, which requires a rating based on process models to obtain contracts. The international standard for describing the method of selecting, implementing, and monitoring the life cycle for software is ISO/IEC 12207.

A decades-long goal has been to find repeatable, predictable processes that improve productivity and quality. Some try to systematize or formalize the seemingly unruly task of designing software. Others apply project management techniques to designing software. Large numbers of software projects do not meet their expectations in terms of functionality, cost, or delivery schedule - see List of failed and overbudget custom software projects for some notable examples.

Organizations may create a Software Engineering Process Group (SEPG), which is the focal point for process improvement. Composed of line practitioners who have varied skills, the group is at the center of the collaborative effort of everyone in the organization who is involved with software engineering process improvement.

A particular development team may also agree to program environment details, such as which integrated development environment is used one or more dominant programming paradigms, programming style rules, or choice of specific software libraries or software frameworks. These details are generally not dictated by the choice of model or general methodology.

 
Software development life cycle (SDLC)

See also

References

  1. ^ a b c d e f g Centers for Medicare & Medicaid Services (CMS) Office of Information Service (2008). Selecting a development approach. Webarticle. United States Department of Health and Human Services (HHS). Re-validated: March 27, 2008. Retrieved 27 Oct 2008.
  2. ^ a b Geoffrey Elliott (2004) Global Business Information Technology: an integrated systems approach. Pearson Education. p.87.
  3. ^ Suryanarayana, Girish (2015). "Software Process versus Design Quality: Tug of War?". IEEE Software. 32 (4): 7–11. doi:10.1109/MS.2015.87.
  4. ^ "software development process". 19 August 2020.
  5. ^ "Continuous Integration".
  6. ^ Booch, Grady (1991). Object Oriented Design: With Applications. Benjamin Cummings. p. 209. ISBN 9780805300918. Retrieved 18 August 2014.
  7. ^ a b Whitten, Jeffrey L.; Lonnie D. Bentley, Kevin C. Dittman. (2003). Systems Analysis and Design Methods. 6th edition. ISBN 0-256-19906-X.
  8. ^ Wasserfallmodell > Entstehungskontext, Markus Rerych, Institut für Gestaltungs- und Wirkungsforschung, TU-Wien. Accessed on line November 28, 2007.
  9. ^ Conrad Weisert, Waterfall methodology: there's no such thing!
  10. ^ Barry Boehm (1996)., "A Spiral Model of Software Development and Enhancement". In: ACM SIGSOFT Software Engineering Notes (ACM) 11(4):14-24, August 1986
  11. ^ Richard H. Thayer, Barry W. Boehm (1986). Tutorial: software engineering project management. Computer Society Press of the IEEE. p.130
  12. ^ Barry W. Boehm (2000). Software cost estimation with Cocomo II: Volume 1.
  13. ^ "Foreword by Jason Fried | Shape Up". basecamp.com. Retrieved 2022-09-11.
  14. ^ "Is Shape Up just a nice theory?". Curious Lab. Retrieved 2022-09-12.
  15. ^ "Principles of Shaping | Shape Up". basecamp.com. Retrieved 2022-09-11.
  16. ^ "Bets, Not Backlogs | Shape Up". basecamp.com. Retrieved 2022-09-11.
  17. ^ "Hand Over Responsibility | Shape Up". basecamp.com. Retrieved 2022-09-11.
  18. ^ "Show Progress | Shape Up". basecamp.com. Retrieved 2022-09-12.
  19. ^ "Atlassian Marketplace". marketplace.atlassian.com. Retrieved 2022-09-12.
  20. ^ Lübke, Daniel; van Lessen, Tammo (2016). "Modeling Test Cases in BPMN for Behavior-Driven Development". IEEE Software. 33 (5): 15–21. doi:10.1109/MS.2016.117. S2CID 14539297.

External links

 
Wikimedia Commons has media related to Software development methodology.
  • Selecting a development approach at cms.hhs.gov.
  • Gerhard Fischer, "The Software Technology of the 21st Century: From Software Reuse to Collaborative Software Design", 2001
  • Subway map of agile practices at Agile Alliance

January 20, 2023
software, development, process, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, js. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Software development process news newspapers books scholar JSTOR December 2010 Learn how and when to remove this template message In software engineering a software development process is a process of dividing software development work into smaller parallel or sequential steps or sub processes to improve design and or product management It is also known as a software development life cycle SDLC The methodology may include the pre definition of specific deliverables and artifacts that are created and completed by a project team to develop or maintain an application 1 Most modern development processes can be vaguely described as agile Other methodologies include waterfall prototyping iterative and incremental development spiral development rapid application development and extreme programming A life cycle model is sometimes considered a more general term for a category of methodologies and a software development process a more specific term to refer to a specific process chosen by a specific organization citation needed For example there are many specific software development processes that fit the spiral life cycle model The field is often considered a subset of the systems development life cycle Contents 1 History 2 Prototyping 3 Methodologies 3 1 Agile development 3 2 Continuous integration 3 3 Incremental development 3 4 Rapid application development 3 5 Waterfall development 3 6 Spiral development 3 7 Shape Up 3 7 1 Cycles 3 7 2 Shaping 3 7 3 Appetite 3 7 4 Building 3 8 Advanced methodologies 4 Process meta models 5 In practice 6 See also 7 References 8 External linksHistory EditThe software development methodology also known as SDM framework didn t emerge until the 1960s According to Elliott 2004 the systems development life cycle SDLC can be considered to be the oldest formalized methodology framework for building information systems The main idea of the SDLC has been to pursue the development of information systems in a very deliberate structured and methodical way requiring each stage of the life cycle from the inception of the idea to delivery of the final system to be carried out rigidly and sequentially 2 within the context of the framework being applied The main target of this methodology framework in the 1960s was to develop large scale functional business systems in an age of large scale business conglomerates Information systems activities revolved around heavy data processing and number crunching routines 2 Methodologies processes and frameworks range from specific prescriptive steps that can be used directly by an organization in day to day work to flexible frameworks that an organization uses to generate a custom set of steps tailored to the needs of a specific project or group In some cases a sponsor or maintenance organization distributes an official set of documents that describe the process Specific examples include 1970sStructured programming since 1969 Cap Gemini SDM originally from PANDATA the first English translation was published in 1974 SDM stands for System Development Methodology1980sStructured systems analysis and design method SSADM from 1980 onwards Information Requirement Analysis Soft systems methodology1990sObject oriented programming OOP developed in the early 1960s and became a dominant programming approach during the mid 1990s Rapid application development RAD since 1991 Dynamic systems development method DSDM since 1994 Scrum since 1995 Team software process since 1998 Rational Unified Process RUP maintained by IBM since 1998 Extreme programming since 19992000sAgile Unified Process AUP maintained since 2005 by Scott Ambler Disciplined agile delivery DAD Supersedes AUP2010s Scaled Agile Framework SAFe Large Scale Scrum LeSS DevOpsIt is notable that since DSDM in 1994 all of the methodologies on the above list except RUP have been agile methodologies yet many organizations especially governments still use pre agile processes often waterfall or similar Software process and software quality are closely interrelated some unexpected facets and effects have been observed in practice 3 Among these another software development process has been established in open source The adoption of these best practices known and established processes within the confines of a company is called inner source Prototyping EditSoftware prototyping is about creating prototypes i e incomplete versions of the software program being developed The basic principles are 1 Prototyping is not a standalone complete development methodology but rather an approach to try out particular features in the context of a full methodology such as incremental spiral or rapid application development RAD Attempts to reduce inherent project risk by breaking a project into smaller segments and providing more ease of change during the development process The client is involved throughout the development process which increases the likelihood of client acceptance of the final implementation While some prototypes are developed with the expectation that they will be discarded it is possible in some cases to evolve from prototype to working system A basic understanding of the fundamental business problem is necessary to avoid solving the wrong problems but this is true for all software methodologies Methodologies EditAgile development Edit Main article Agile software development Agile software development refers to a group of software development frameworks based on iterative development where requirements and solutions evolve via collaboration between self organizing cross functional teams The term was coined in the year 2001 when the Agile Manifesto was formulated Agile software development uses iterative development as a basis but advocates a lighter and more people centric viewpoint than traditional approaches Agile processes fundamentally incorporate iteration and the continuous feedback that it provides to successively refine and deliver a software system The Agile model also includes the following software development processes 4 Dynamic systems development method DSDM Kanban Scrum Crystal Atern Lean software developmentContinuous integration Edit Main article Continuous integration Continuous integration is the practice of merging all developer working copies to a shared mainline several times a day 5 Grady Booch first named and proposed CI in his 1991 method 6 although he did not advocate integrating several times a day Extreme programming XP adopted the concept of CI and did advocate integrating more than once per day perhaps as many as tens of times per day Incremental development Edit Main article Iterative and incremental development Various methods are acceptable for combining linear and iterative systems development methodologies with the primary objective of each being to reduce inherent project risk by breaking a project into smaller segments and providing more ease of change during the development process There are three main variants of incremental development 1 A series of mini Waterfalls are performed where all phases of the Waterfall are completed for a small part of a system before proceeding to the next increment or Overall requirements are defined before proceeding to evolutionary mini Waterfall development of individual increments of a system or The initial software concept requirements analysis and design of architecture and system core are defined via Waterfall followed by incremental implementation which culminates in installing the final version a working system Rapid application development Edit Main article Rapid application development Rapid Application Development RAD Model Rapid application development RAD is a software development methodology which favors iterative development and the rapid construction of prototypes instead of large amounts of up front planning The planning of software developed using RAD is interleaved with writing the software itself The lack of extensive pre planning generally allows software to be written much faster and makes it easier to change requirements The rapid development process starts with the development of preliminary data models and business process models using structured techniques In the next stage requirements are verified using prototyping eventually to refine the data and process models These stages are repeated iteratively further development results in a combined business requirements and technical design statement to be used for constructing new systems 7 The term was first used to describe a software development process introduced by James Martin in 1991 According to Whitten 2003 it is a merger of various structured techniques especially data driven information technology engineering with prototyping techniques to accelerate software systems development 7 The basic principles of rapid application development are 1 Key objective is for fast development and delivery of a high quality system at a relatively low investment cost Attempts to reduce inherent project risk by breaking a project into smaller segments and providing more ease of change during the development process Aims to produce high quality systems quickly primarily via iterative Prototyping at any stage of development active user involvement and computerized development tools These tools may include Graphical User Interface GUI builders Computer Aided Software Engineering CASE tools Database Management Systems DBMS fourth generation programming languages code generators and object oriented techniques Key emphasis is on fulfilling the business need while technological or engineering excellence is of lesser importance Project control involves prioritizing development and defining delivery deadlines or timeboxes If the project starts to slip emphasis is on reducing requirements to fit the timebox not in increasing the deadline Generally includes joint application design JAD where users are intensely involved in system design via consensus building in either structured workshops or electronically facilitated interaction Active user involvement is imperative Iteratively produces production software as opposed to a throwaway prototype Produces documentation necessary to facilitate future development and maintenance Standard systems analysis and design methods can be fitted into this framework Waterfall development Edit Main article Waterfall model The activities of the software development process represented in the waterfall model There are several other models to represent this process The waterfall model is a sequential development approach in which development is seen as flowing steadily downwards like a waterfall through several phases typically Requirements analysis resulting in a software requirements specification Software design Implementation Testing Integration if there are multiple subsystems Deployment or Installation MaintenanceThe first formal description of the method is often cited as an article published by Winston W Royce 8 in 1970 although Royce did not use the term waterfall in this article Royce presented this model as an example of a flawed non working model 9 The basic principles are 1 The Project is divided into sequential phases with some overlap and splash back acceptable between phases Emphasis is on planning time schedules target dates budgets and implementation of an entire system at one time Tight control is maintained over the life of the project via extensive written documentation formal reviews and approval signoff by the user and information technology management occurring at the end of most phases before beginning the next phase Written documentation is an explicit deliverable of each phase The waterfall model is a traditional engineering approach applied to software engineering A strict waterfall approach discourages revisiting and revising any prior phase once it is complete according to whom This inflexibility in a pure waterfall model has been a source of criticism by supporters of other more flexible models It has been widely blamed for several large scale government projects running over budget over time and sometimes failing to deliver on requirements due to the Big Design Up Front approach according to whom Except when contractually required the waterfall model has been largely superseded by more flexible and versatile methodologies developed specifically for software development according to whom See Criticism of Waterfall model Spiral development Edit Spiral model Boehm 1988 Main article Spiral model In 1988 Barry Boehm published a formal software system development spiral model which combines some key aspects of the waterfall model and rapid prototyping methodologies in an effort to combine advantages of top down and bottom up concepts It provided emphasis in a key area many felt had been neglected by other methodologies deliberate iterative risk analysis particularly suited to large scale complex systems The basic principles are 1 Focus is on risk assessment and on minimizing project risk by breaking a project into smaller segments and providing more ease of change during the development process as well as providing the opportunity to evaluate risks and weigh consideration of project continuation throughout the life cycle Each cycle involves a progression through the same sequence of steps for each part of the product and for each of its levels of elaboration from an overall concept of operation document down to the coding of each individual program 10 Each trip around the spiral traverses four basic quadrants 1 determine objectives alternatives and constraints of the iteration and 2 evaluate alternatives Identify and resolve risks 3 develop and verify deliverables from the iteration and 4 plan the next iteration 11 Begin each cycle with an identification of stakeholders and their win conditions and end each cycle with review and commitment 12 Shape Up Edit Shape Up is a software development approach introduced by Basecamp in 2018 It is a set of principles and techniques that Basecamp developed internally to overcome the problem of projects dragging on with no clear end Its primary target audience is remote teams Shape Up has no estimation and velocity tracking backlogs or sprints unlike Waterfall Agile or Scrum Instead those concepts are replaced with appetite betting and cycles As of 2022 besides Basecamp notable organizations that have adopted Shape Up include UserVoice and Block 13 14 Cycles Edit Through trials and errors Basecamp found that the ideal cycle length is 6 weeks This 6 week period is long enough to build a meaningful feature and still short enough to induce a sense of urgency Shaping Edit Shaping is the process of preparing work before being handed over to designers and engineers Shaped work spells out the solution s main UI elements identifies rabbit holes and outlines clear scope boundaries It is meant to be rough and to leave finer details for builders designers and engineers to solve allowing the builders to exercise their creativity and make trade offs 15 Shaped work is documented in the form of a pitch using an online document solution that supports commenting allowing team members to contribute technical information asynchronously Such comments are crucial for uncovering hidden surprises that may derail the project Before a cycle begins stakeholders hold a betting table where pitches are reviewed For each pitch a decision is made to either bet on it or drop it 16 Appetite Edit The way Shape Up determines how much time is allocated to a project is diametrically opposed to other methodologies Shape Up starts with an appetite for example 6 weeks and ends with a solution design that can be delivered within this constraint The appetite becomes a hard deadline for the project s builders 17 Building Edit Shape Up is a two track system where shapers and builders work in parallel Work that is being shaped in the current cycle may be given to designers and engineers to build in a future cycle Recognizing the technical uncertainties that come with building progress is tracked using a chart that visualizes the metaphor of the hill aptly named the hill chart The uphill phase is where builders are still working out their approach while the downhill is where unknowns have been eliminated Builders proactively and asynchronously self report progress using an interactive online hill chart on Basecamp or Jira shifting focus from done or not done statuses to unknown or solved problems The use of hill chart replaces the process of reporting linear statuses in scrum or Kanban standup 18 19 Advanced methodologies Edit Other high level software project methodologies include Behavior driven development and business process management 20 Chaos model The main rule always resolve the most important issue first Incremental funding methodology an iterative approach Lightweight methodology a general term for methods that only have a few rules and practices Structured systems analysis and design method a specific version of waterfall Slow programming as part of the larger Slow Movement emphasizes careful and gradual work without or minimal time pressures Slow programming aims to avoid bugs and overly quick release schedules V Model software development an extension of the waterfall model Unified Process UP is an iterative software development methodology framework based on Unified Modeling Language UML UP organizes the development of software into four phases each consisting of one or more executable iterations of the software at that stage of development inception elaboration construction and guidelines Many tools and products exist to facilitate UP implementation One of the more popular versions of UP is the Rational Unified Process RUP Big Bang methodology an approach for small or undefined projects generally consisting of little to no planning with high risk Process meta models EditSome process models are abstract descriptions for evaluating comparing and improving the specific process adopted by an organization ISO IEC 12207 is the international standard describing the method to select implement and monitor the life cycle for software The Capability Maturity Model Integration CMMI is one of the leading models and is based on best practices Independent assessments grade organizations on how well they follow their defined processes not on the quality of those processes or the software produced CMMI has replaced CMM ISO 9000 describes standards for a formally organized process to manufacture a product and the methods of managing and monitoring progress Although the standard was originally created for the manufacturing sector ISO 9000 standards have been applied to software development as well Like CMMI certification with ISO 9000 does not guarantee the quality of the end result only that formalized business processes have been followed ISO IEC 15504 Information technology Process assessment is also known as Software Process Improvement Capability Determination SPICE is a framework for the assessment of software processes This standard is aimed at setting out a clear model for process comparison SPICE is used much like CMMI It models processes to manage control guide and monitors software development This model is then used to measure what a development organization or project team actually does during software development This information is analyzed to identify weaknesses and drive improvement It also identifies strengths that can be continued or integrated into common practice for that organization or team ISO IEC 24744 Software Engineering Metamodel for Development Methodologies is a power type based metamodel for software development methodologies SPEM 2 0 by the Object Management Group Soft systems methodology a general method for improving management processes Method engineering a general method for improving information system processes Further information Process patternsIn practice Edit The three basic approaches applied to software development methodology frameworks A variety of such frameworks have evolved over the years each with its own recognized strengths and weaknesses One software development methodology framework is not necessarily suitable for use by all projects Each of the available methodology frameworks is best suited to specific kinds of projects based on various technical organizational project and team considerations 1 Software development organizations implement process methodologies to ease the process of development Sometimes contractors may require methodologies employed an example is the U S defense industry which requires a rating based on process models to obtain contracts The international standard for describing the method of selecting implementing and monitoring the life cycle for software is ISO IEC 12207 A decades long goal has been to find repeatable predictable processes that improve productivity and quality Some try to systematize or formalize the seemingly unruly task of designing software Others apply project management techniques to designing software Large numbers of software projects do not meet their expectations in terms of functionality cost or delivery schedule see List of failed and overbudget custom software projects for some notable examples Organizations may create a Software Engineering Process Group SEPG which is the focal point for process improvement Composed of line practitioners who have varied skills the group is at the center of the collaborative effort of everyone in the organization who is involved with software engineering process improvement A particular development team may also agree to program environment details such as which integrated development environment is used one or more dominant programming paradigms programming style rules or choice of specific software libraries or software frameworks These details are generally not dictated by the choice of model or general methodology Software development life cycle SDLC See also EditSystems development life cycle Computer aided software engineering some of these tools support specific methodologies List of software development philosophies Outline of software engineering OpenUP Project management Software development Software development effort estimation Software release life cycle Top down and bottom up design Computer scienceReferences Edit a b c d e f g Centers for Medicare amp Medicaid Services CMS Office of Information Service 2008 Selecting a development approach Webarticle United States Department of Health and Human Services HHS Re validated March 27 2008 Retrieved 27 Oct 2008 a b Geoffrey Elliott 2004 Global Business Information Technology an integrated systems approach Pearson Education p 87 Suryanarayana Girish 2015 Software Process versus Design Quality Tug of War IEEE Software 32 4 7 11 doi 10 1109 MS 2015 87 software development process 19 August 2020 Continuous Integration Booch Grady 1991 Object Oriented Design With Applications Benjamin Cummings p 209 ISBN 9780805300918 Retrieved 18 August 2014 a b Whitten Jeffrey L Lonnie D Bentley Kevin C Dittman 2003 Systems Analysis and Design Methods 6th edition ISBN 0 256 19906 X Wasserfallmodell gt Entstehungskontext Markus Rerych Institut fur Gestaltungs und Wirkungsforschung TU Wien Accessed on line November 28 2007 Conrad Weisert Waterfall methodology there s no such thing Barry Boehm 1996 A Spiral Model of Software Development and Enhancement In ACM SIGSOFT Software Engineering Notes ACM 11 4 14 24 August 1986 Richard H Thayer Barry W Boehm 1986 Tutorial software engineering project management Computer Society Press of the IEEE p 130 Barry W Boehm 2000 Software cost estimation with Cocomo II Volume 1 Foreword by Jason Fried Shape Up basecamp com Retrieved 2022 09 11 Is Shape Up just a nice theory Curious Lab Retrieved 2022 09 12 Principles of Shaping Shape Up basecamp com Retrieved 2022 09 11 Bets Not Backlogs Shape Up basecamp com Retrieved 2022 09 11 Hand Over Responsibility Shape Up basecamp com Retrieved 2022 09 11 Show Progress Shape Up basecamp com Retrieved 2022 09 12 Atlassian Marketplace marketplace atlassian com Retrieved 2022 09 12 Lubke Daniel van Lessen Tammo 2016 Modeling Test Cases in BPMN for Behavior Driven Development IEEE Software 33 5 15 21 doi 10 1109 MS 2016 117 S2CID 14539297 External links Edit Wikimedia Commons has media related to Software development methodology Selecting a development approach at cms hhs gov Gerhard Fischer The Software Technology of the 21st Century From Software Reuse to Collaborative Software Design 2001 Subway map of agile practices at Agile Alliance Retrieved from https en wikipedia org w index php title Software development process amp oldid 1133929573, wikipedia, wiki, book, books, 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