On-the-fly conformance testing of safety PLC code using QuickCheck

In this paper, an approach based on the IOCOS testing relation to test safety PLC code using the tool QuickCheck is presented. Testing and validation of the safety PLC code is typically carried out on a physical system using checklists. These checklists are developed by engineers using system specification. However, due to the manual nature of checklist generation and execution, certain test cases can be overlooked and can lead to human accidents. The presented approach allows on-the-fly generation and execution of test cases, which expands the scope of testing by including test cases unconceived during checklist generation. Furthermore, it is demonstrated how errors in the safety PLC code are uncovered based on the IOCOS relation.