Automatic Test Suite Generation for PLC Software in the Internet of Production

Abstract

Automatic test suite generation is an established technique used to generate test suites adhering to structural coverage metrics of PLC software. In order to reduce redundancy in the test suite generation after a structural reconfiguration to the PLC software has occurred, reusable summaries of program parts should be employed. This paper presents a combination of state-of-the-art symbolic execution and static analysis algorithms for test suite generation and summary reuse. The general rationale is to improve efficiency by not doing redundant work. For this purpose, summaries of function blocks are cached and reused to benefit from the previous analysis. As code untouched from reconfigurations will result in equivalent path conditions summaries can aid in speeding up regression testing. The proto-typical implementations of several techniques are evaluated and compared using selected domain-specific benchmarks showing the ineffectiveness of using summarization during test suite generation for reconfigurable logic control software.