As we discussed in Chapter 1, the Systems Development Life Cycle (SDLC) provides
the foundation for the processes used to develop an information system. A methodology
is a formalized approach to implementing the SDLC (i.e., it is a list of steps and
deliverables). There are many different systems development methodologies, and they
vary in terms of the progression that is followed through the phases of the SDLC.
Some methodologies are formal standards used by government agencies, while others
have been developed by consulting firms to sell to clients. Many organizations have
their own internal methodologies that have been refined over the years, and they
explain exactly how each phase of the SDLC is to be performed in that company. Here
we will review several of the predominant methodologies that have evolved over time.