Using Interdependencies for the Prioritization and Reprioritization of Requirements in Incremental Development

Abstract

There is a growing trend to develop and deliver the software in an incremental manner; to achieve greater consistency in the developed software and better customer satisfaction during the requirement engineering process. Some of the developed increments in the incremental model will be delivered to consumers and run in their environments, so a set of these requirements are evaluated, introduced, and delivered as the first increment. Other requirements are delivered as the next step and so on for the next increment. The priority of requirements plays an important role in each increment, but it is precluded by the interdependences between the requirements and resources constraints. Therefore, this paper introduces a model for requirements prioritization and a reprioritization based on these important factors. The first one is the requirement interdependencies which are described as a hybrid approach of tractability list and directed acyclic graph, and the second factor is the constraints of the requirements resources that are used based on the queuing theory for requirements reprioritization. In order to achieve this, two algorithms namely; Priority Dependency Graph (PDG) and Resources Constraints Reprioritization (RCR), were proposed with a linear time complexity and implemented via a case study.