Evaluating the Impact of Upfront Identification of D Requirements on Computer-Based System Quality and Development Time in Agile Context

Abstract

Empirical studies show that requirements defects are among the most common causes of computer-based system (CBS) failures, and that fixing these defects becomes increasingly expensive as CBS development progresses. This has fueled a longstanding debate about whether requirements for a CBS should be identified upfront before beginning any coding, as in the waterfall methods, or incrementally, as in the agile methods. To resolve this dilemma, Berry et al. argue that both sides are right, but each is about a different kind of requirement, (1) scope determineD (D) or (2) scope determininG (G), respectively, and claim that D requirements should be identified upfront while G requirements can be identified incrementally. They hypothesized that a CBS development using a modified agile method (MAM), in which all D requirements for a sprint's scope are identified before implementation begins, will lead to a faster and less buggy implementation than a development using a normal agile method (NAM), in which implementation begins as soon as the sprint's scope is identified. This research tests this hypothesis through a controlled experiment using experiment-sized chunks of MAM and NAM, called mini MAM (mMAM) and mini NAM (mNAM), as proxies of the entire methods. This research contributes the first empirical evidence on the hypothesis, and a method for testing hypotheses comparing full-lifecycle development methods at experiment scale.