Formal specification of UML models in OCL is essential to improve software quality. Owing to the use of OCL in precise model specification, its application has been looked in different perspectives such as early measurement of module complexity. Moreover, when UML class diagrams are complemented with OCL, the metrics collected from OCL specification can serve as an indicator of fault-prone components. In the proposed approach an empirical study has been conducted on five soft real time case study applications. In this paper, existing metrics which are applicable to OCL expression are validated using module complexity. Moreover, a new metrics suite, which can be extracted from OCL expressions, has been devoted to quantify module complexity. The proposed metrics suite can be directly extracted from OCL expressions. Relative weight has been assigned to each metric which is selected for the proposed study, based on its importance in fault-prone components identification. The study shows that an analysis on OCL formal specification based metrics is effective in identifying fault-prone components of the system. Furthermore, it helps to distribute efforts required for software development and testing activities.
Empirical study on the difficulties of software modeling through class diagrams
