Is there a preferred model for information life cycles?
The policy statements in this Circular describe an information system life cycle. It does not, however, make a definitive statement that there must be, for example, four versus five phases of a life cycle because the life cycle varies by the nature of the information system. Only two phases are common to all information systems – a beginning and an end. While each phase of an information system life cycle may have unique characteristics, the dividing line between the phases may not always be distinct. For instance, both planning and evaluation must continue throughout the information system life cycle. In fact, during any phase, it may be necessary to revisit the previous stages based on new information or changes in the environment in which the system is being developed. Why are post-implementation reviews necessary? Agencies will complete a retrospective evaluation of information systems once operational to validate projected savings, changes in practices, and effectiveness in servin
