Wikipedia

Software development process

This is an old revision of this page, as edited by Stevebroshar (talk | contribs) at 13:55, 27 July 2025 (Order by popularity). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

A software development process prescribes a process for developing software. It typically divides an overall effort into smaller steps or sub-processes that are intended to ensure high-quality results. The process may describe specific deliverables – artifacts to be created and completed.[1]

The system development life cycle (SDLC) describes the typical phases that a development effort goes through from the beginning to the end of life for a system – including a software system. A development process prescribes how engineers go about their work in order to move the system through its life cycle. An SDLC methodology (a.k.a. model, framework) is a classification of processes or a blueprint for a process that is devised for the SDLC. For example, many software development processes can be classified as the spiral model. Process methodologies include: agile, waterfall, prototyping, iterative and incremental development, spiral development, rapid application development, and extreme programming.

History

The SDLC was first described in the 1960s, and was often conflated with the waterfall model for many years. According to Elliott (2004), the SDLC [waterfall model] can be considered the oldest formalized methodology 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 goal of this methodology 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] Other methodologies were devised later:

1970s
1980s
1990s
2000s
2010s

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.

Methodologies

The following are notable methodologies somewhat ordered by popularity.

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:

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.[4] Grady Booch first named and proposed CI in his 1991 method,[5] 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.

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[6] 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.[7]

The basic principles are:[1]

  • The Project is divided into sequential phases, with some overlap and splashback 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 on 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."[8]
  • 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.[9]
  • Begin each cycle with an identification of stakeholders and their "win conditions", and end each cycle with review and commitment.[10]

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.

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.

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".[11]

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.[11]

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, the emphasis is on reducing requirements to fit the timebox, not on 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.

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.[12][13]

Advanced methodologies

Other high-level software project methodologies include:

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 monitor 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.
  • Soft systems methodology - a general method for improving management processes.
  • Method engineering - a general method for improving information system processes.
Further information: Process patterns

See also

References

  1. ^ a b c d e f "Selecting a development approach" (PDF). Centers for Medicare & Medicaid Services (CMS) Office of Information Service. United States Department of Health and Human Services (HHS). March 27, 2008 [Original Issuance: February 17, 2005]. Archived from the original (PDF) on June 20, 2012. Retrieved October 27, 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. ^ Paul M. Duvall; Steve Matyas; Andrew Glover (2007). Continuous Integration: Improving Software Quality and Reducing Risk. Addison-Wesley Professional. ISBN 978-0-321-33638-5.
  5. ^ Booch, Grady (1991). Object Oriented Design: With Applications. Benjamin Cummings. p. 209. ISBN 9780805300918. Retrieved August 18, 2014.
  6. ^ Markus Rerych. "Wasserfallmodell > Entstehungskontext". Institut für Gestaltungs- und Wirkungsforschung, TU-Wien (in German). Retrieved November 28, 2007.
  7. ^ Conrad Weisert. "Waterfall methodology: there's no such thing!". Archived from the original on August 2, 2022.
  8. ^ Barry Boehm (August 1986). "A Spiral Model of Software Development and Enhancement". ACM SIGSOFT Software Engineering Notes. 11 (4). Association for Computing Machinery: 14–24. doi:10.1145/12944.12948. S2CID 1781829.
  9. ^ Richard H. Thayer; Barry W. Boehm (1986). Tutorial: software engineering project management. Computer Society Press of the IEEE. p. 130.
  10. ^ Barry W. Boehm (2000). Software cost estimation with Cocomo II: Volume 1.
  11. ^ a b Whitten, Jeffrey L.; Lonnie D. Bentley, Kevin C. Dittman. (2003). Systems Analysis and Design Methods. 6th edition. ISBN 0-256-19906-X.
  12. ^ "Foreword by Jason Fried | Shape Up". basecamp.com. Retrieved September 11, 2022.
  13. ^ "Is Shape Up just a nice theory?". Curious Lab. Retrieved September 12, 2022.
  14. ^ 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.
 
Wikimedia Commons has media related to Software development methodology.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Software_development_process&oldid=1302795866"