RiTMO: Runtime Testability Measurement and Optimisation

Runtime testing is emerging as the solution for the integration and assessment of highly dynamic, high availability software systems where traditional development-time integration testing is too costly, or cannot be performed. However, in many situations, an extra cost will have to be invested in implementing appropriate measures to enable runtime tests to be performed without affecting the running system or its environment. This paper introduces a method for the improvement of the runtime testability of a system, which provides an optimal action plan considering the trade-off between testability and implementation cost. The computation of the action plan is driven by an estimation of runtime testability, and based on a model of the system. Runtime testability is estimated independently of the test cases and focused exclusively on the test-relevant features of the system. This method is used to direct integrationand testengineers in the implementation of improvement measures for the runtime testability during the integration of a system. Furthermore, it can also be applied earlier, on the design stage, providing a Design for Testability method for dynamic systems. By means of an example, we demonstrate how our method enables an optimal expenditure of resources towards runtime testability during the integration phase of a system.