Formal test requirements for component interactions

A major issue in testing the integration of software components is the selection of tests to ensure that the components work together correctly. The goal is to detect subtle interaction errors without duplicating the work performed in unit testing. Our approach is to capture the assumptions made by each component about how other components should interact with it. The assumptions are captured as formal test requirements that specify what test cases are needed to exercise the interactions. We model the interactions of components using a simple mathematical model that allows concurrency and synchronous communications. The test requirements, together with formal models of the components, are used to generate actual test cases for integration testing. They can be reused when more components are integrated, and when components are changed.