Towards mutation analysis for use cases

Requirements inspection is a well-known method for detecting defects. Various defect detection techniques for requirements inspection have been widely applied in practice such as checklist and defect-based techniques. Use case modelling is a widely accepted requirements specification method in practice; therefore, inspecting defects in use case models in a cost-effective manner is an important challenge. However, it does not exist a systematic mutation analysis approach for evaluating inspection techniques for use case models. In this paper we present the methodology we followed to systematically derive mutation operators for use case models. More specifically, we first proposed a defect taxonomy defining 94 defect types, based on the IEEE Std. 830-1998 standard. Second, we systematically applied the basic guide words of the standardized Hazard and Operability Study (HAZOP) methodology to define 191 mutation operators. Last, we defined a set of guidelines for devising defect seeding strategies. The proposed methodology was evaluated by a real world case study and six case studies from the literature. Results show that all the derived mutation operators for Restricted Use Case Modelling (RUCM) models are feasible to apply and the defect taxonomy is the most comprehensive one to compare with the literature.