Consistency Checking of Specification in UML

Abstract

The increasing use of software is giving rise to the development of highly complex software systems. Further, software systems are required to be of high quality as a defect can have catastrophic effect on business as well as human life. Testing is defined as the process of executing a program with the intention of finding errors. Software testing is an expensive process of the software development life cycle consuming nearly 50% of development cost. Software testing aims not only to guarantee consistency in software specification but also to validate its implementation meeting user requirements. On the whole, it is observed that in general, errors in software systems set in at the early stages of the software development cycle (i.e. while gathering user requirements and deciding on specification of intended software). Even though formal specification in B and Z assures a provable system, its use has become less popular due to mathematical rigor. The Unified Modeling Language (UML), a semi-formal language with graphical notations consisting of various diagrams has caught software developers’ imaginations and, it has become popular in industry. UML, with its several diagrams, helps to develop a model of intended software, and the model behaviour is simulated and tested to the satisfaction of both developer as well as users. As a UML model includes specifications of different aspects of a software system through several diagrams, it is essential to maintain consistency among diagrams so that quality of the model is maintained, and through inconsistency checking and removal, the model moves toward completeness. The works reported in literature on this topic are reviewed here.