Scenario-based test case generation for state-based embedded systems

To reduce testing cost and effort, the paper proposes a systematic approach to generate test cases for state-based embedded systems. This process first derives a state/event tree based on a scenario specification, with a node of the tree representing a state, and a link a transition between two states. Once the tree is obtained, it is possible to generate test inputs based on partition testing, random testing and boundary value testing. It is also possible to perform various analyses such as completeness and consistency analysis, dependency analysis and relationship analysis. An XML-based tool has been developed to automate many of the steps in the process. Whenever there is a change to the system, the tester needs to modify the state/event tree, and the tool automatically re-generates the new test cases to test those changed parts as well as perform selective regression testing to test those affected parts. To illustrate the ideas, the paper uses a wireless mobile phone system as an example. The system consists of three parts: a mobile station center server, several base station servers, and clients.