Test cost minimisation approaches have traditionally been devoted to minimising ``execution costs'', while maximising coverage or reliability. However, in a runtime testing context, the amount of coverage or reliability that can be achieved, in other words, the system's Runtime Testability, is limited by the adverse effects that the interferences of runtime tests have on the system. Supporting runtime testing, therefore, introduces an additional cost in ``preparatory'' activities in software, (e.g., testable components) and in hardware (e.g., more memory), before certain runtime tests can be executed. In this paper we present a low-complexity, cost minimisation algorithm for the optimal selection of preparation activities, based on a near-optimal trade-off between preparation cost and a structure-based measurement of Runtime Testability, coined the Runtime Testability Metric (RTM). We perform a theoretical and empirical validation of RTM, showing that RTM is indeed a valid, and reasonably accurate measurement with ratio scale. We also present empirical data demonstrating the near-optimal performance at a low computational cost of our algorithm.
['Alberto Gonzalez-Sanchez', 'Éric Piel', 'Hans-Gerhard Gross', 'Arjan J. C. van Gemund']
Minimising the Preparation Cost of Runtime Testing Based on Testability Metrics