<P> SDLC can be described along a spectrum of agile to iterative to sequential methodologies . Agile methodologies, such as XP and Scrum, focus on lightweight processes which allow for rapid changes (without necessarily following the pattern of SDLC approach) along the development cycle . Iterative methodologies, such as Rational Unified Process and dynamic systems development method, focus on limited project scope and expanding or improving products by multiple iterations . Sequential or big - design - up - front (BDUF) models, such as waterfall, focus on complete and correct planning to guide large projects and risks to successful and predictable results . Other models, such as anamorphic development, tend to focus on a form of development that is guided by project scope and adaptive iterations of feature development . </P> <P> In project management a project can be defined both with a project life cycle (PLC) and an SDLC, during which slightly different activities occur . According to Taylor (2004), "the project life cycle encompasses all the activities of the project, while the systems development life cycle focuses on realizing the product requirements". </P> <P> SDLC is used during the development of an IT project, it describes the different stages involved in the project from the drawing board, through the completion of the project . </P> <P> The SDLC is not a methodology per se, but rather a description of the phases in the life cycle of a software application . These phases (broadly speaking) are, investigation, analysis, design, build, test, implement, and maintenance and support . All software development methodologies (such as the more commonly known waterfall and scrum methodologies) follow the SDLC phases but the method of doing that varies vastly between methodologies . In the Scrum methodology, for example, one could say a single user story goes through all the phases of the SDLC within a single two - week sprint . Contrast this to the waterfall methodology, as another example, where every business requirement (recorded in the analysis phase of the SDLC in a document called the Business Requirements Specification) is translated into feature / functional descriptions (recorded in the design phase in a document called the Functional Specification) which are then all built in one go as a collection of solution features typically over a period of three to nine months, or more . These methodologies are obviously quite different approaches yet, they both contain the SDLC phases in which a requirement is born, then travels through the life cycle phases ending in the final phase of maintenance and support, after - which (typically) the whole life cycle starts again for a subsequent version of the software application . </P>

What are the phases of the system development life cycle