“The systems development life cycle (SDLC) describes the typical phases and progression between phases during the development of a computer-based system; from inception to retirement. At base, there is just one life cycle even though there are different ways to describe it; using differing numbers of and names for the phases. The SDLC is analogous to the life cycle of a living organism from its birth to its death. In particular, the SDLC varies by system in much the same way that each living organism has a unique path through its life.
The SDLC does not prescribe how engineers should go about their work to move the system through its life cycle. Prescriptive techniques are referred to using various terms such as methodology, model, framework, and formal process.”