Are the principal advantages and disadvantages of the sequential approach to system development offered through the waterfall and ‘V’ lifecycle models?

The waterfall approach and its ‘V’ model variant suggest a logical set of steps which have to be pursued to implement and develop a system. They give good control for a project way when, in theory at any rate every stage must be finish and signed off through the project sponsor before proceeding to the subsequent. This also implies that every stage builds appropriately on its predecessor and therefore assists into the creation of a high-quality deliverable. The models useful into resource deployment as this is easier to notice what skills are required at every stage of business or of systems analysis throughout needs analysis, designers throughout the design stages and development throughout code and test and many. The ‘V’ model has the additional benefit that this demonstrates explicitly the connections in between the earlier and later project stages among needs specification and user acceptance for instance.

The major drawbacks of these approaches are which projects undertaken along with them can take quite a long time from inception to delivery and it is frequently not very appropriate for modern business circumstances, where change is constant and incessant. Along with the linear approaches, changes which arise later into the project are complicated to accommodate when the earlier stages must be revisited to reflect the changes. At last, these approaches do suppose, as a starting point, which the users can identify in some detail what they wish for their new system whereas in several cases, for example, where a system is required to meet an unprecedented business circumstances, it is very far by being the case. Where this uncertainty exists, an evolutionary lifecycle or the spiral is probably more appropriate.