A study of requirements change effects on incrementally delivered systems

A study is made of the impact of requirements changes on systems of equivalent functionality but with a different underlying development paradigm. An incremental delivery paradigm is compared to the traditional top-down complete development paradigm. The study seeks to determine the existence and possible nature of any significant differences in cost between the incremental delivery paradigm and the traditional development paradigm. To do so, the general form of an experimental process including six trials that involved single programmers is outlined. The programmers made modifications, based on new specifications, to two equivalent systems, each constructed according to one of the two paradigms, until the altered programs once again functioned as expected. The size of the changes and effort expended was recorded and tabulated to reflect the `cost´ of maintenance updates in both paradigms. The results of the study are analyzed, and the outcomes can be used to explore future research directions for incremental delivery methodologies