A Merging-Based Approach to Handling Inconsistency in Locally Prioritized Software Requirements

It has been widely recognized that the relative priority of requirements can help developers to resolve inconsistencies and make some necessary trade-off decisions. However, for most distributed development such as Viewpoints-based approaches, different stakeholders may assign different levels of priority to the same shared requirements statement from their own perspectives. The disagreement in the local priorities assigned to the same shared requirements statement often puts developers into a dilemma during inconsistency handling process. As a solution to this problem, we present a merging-based approach to handling inconsistency in the Viewpoints framework in this paper. In the Viewpoints framework, each viewpoint is a requirements collection with local prioritization. Informally, we transform such a requirements collection with local prioritization into a stratified knowledge base. Moreover, the relationship between viewpoints is considered as integrity constraints. By merging these stratified knowledge bases, we then construct a merged knowledge base with a global prioritization, which may be viewed as an overall belief in these viewpoints. Finally, proposals for inconsistency handling are derived from the merged result. The global prioritization as well as the local prioritization may be used to argue these proposals and to help developers make a reasonable trade-off decision on handling inconsistency.