Using Colored Petri Nets for System Specifications and as a System Under Test Prototype

Abstract

Automated testing is an essential part in the software development process. It requires, however, the system under test (SUT) to be at least partially implemented. Also the practical verification of the test cases themselves cannot start before the SUT is available. Based on the usage of Colored Petri Nets (CPNs) as a specification tool and their integration with TTCN-3, we present an approach allowing test case application and validation already before the start of the implementation phase. As an additional benefit, the well-defined semantics of CPNs enforces a more complete, explicit, and consistent system specification. Since CPNs also provide an intuitive visual representation of the model, they facilitate communication of the system specifications among various stakeholders throughout the development process. To gain more confidence in the correctness of the specification as well as the test implementation, the new idea was to apply identical TTCN-3 tests already in the system specification phase against the formal, executable CPN model and again later against the implemented system. The implementation of the described approach is based on the development of the machine control software for banknote processing systems.