Experiences from Adjusting Industrial Software for Worst-Case Execution Time Analysis

Worst-case execution time (WCET) analysis is a prevalent way to ensure the timely execution of programs in time-critical systems. With the advent of new technologies such as fog computing and time-sensitive networking (TSN), the interest in timing analysis has increased in industrial communication. This paper highlights experiences made while adjusting the publisher of the open62541 OPC UA stack to enable WCET analysis, following a simple process combined with the open-source platform T-CREST. The main challenges are the required knowledge about the code and the specific communication software characteristics like variable message sizes. Other findings indicate the need for other types of annotation for indirect recursion or callback functions. The paper provides the foundation for further research on adjusting the implementation of existing industrial communication protocols for WCET analysis.