Experiences from Industrial WCET Analysis Case Studies

Static Worst-Case Execution Time (WCET) analysis is currently taking a step from research to industrial use. We present a summary of three case studies where static WCET analysis has been used to analyse production code for embedded real-time systems. The primary purpose has not been to test the accuracy of the obtained WCET estimates, but rather to investigate the practical and methodological difficulties that arise when applying current WCET analysis methods to these particular kind of systems. In particular, we have been interested in how laborintensive the analysis becomes, for instance by estimating the efforts to study the analysed code in detail, and measuring the number of manual annotations necessary to perform the analysis. From these observations, we draw some conclusions about what would be needed to turn static WCET analysis into a useful tool for embedded and real-time systems software development.