You are required to read and agree to the below before accessing a full-text version of an article in the IDE article repository.

The full-text document you are about to access is subject to national and international copyright laws. In most cases (but not necessarily all) the consequence is that personal use is allowed given that the copyright owner is duly acknowledged and respected. All other use (typically) require an explicit permission (often in writing) by the copyright owner.

For the reports in this repository we specifically note that

  • the use of articles under IEEE copyright is governed by the IEEE copyright policy (available at
  • the use of articles under ACM copyright is governed by the ACM copyright policy (available at
  • technical reports and other articles issued by M‰lardalen University is free for personal use. For other use, the explicit consent of the authors is required
  • in other cases, please contact the copyright owner for detailed information

By accepting I agree to acknowledge and respect the rights of the copyright owner of the document I am about to access.

If you are in doubt, feel free to contact

An Industrial Study on Automated Test Generation and Manual Testing of IEC 61131-3 Software


Publication Type:

Report - MRTC


Mälardalen Real-Time Research Centre, Mälardalen University




The recent maturation of techniques and tools for automated test generation offers the opportunity to produce test suites with high code coverage in a matter of seconds. Nonetheless, it is not very well studied how such test suites compare to manually written ones in terms of cost and effectiveness. To a certain extent such comparisons have been made using open-source programs. However, evidence on how automated coverage-directed test generation could be used for industrial software is sparse. This is particularly true for industrial control software, where strict requirements on both specification-based testing and code coverage typically are met with rigorous manual testing. To address this issue, we conducted a case study in which we compared the cost and effectiveness between manually and automatically created test suites. In particular, we measured the cost and effectiveness in terms of fault detection of test suites created using a coverage-directed automated test generation tool and test suites manually created by industrial engineers for an existing train control system. We used recently developed real-world industrial programs written in the IEC 61131-3 FBD, a popular programming language for developing safety-critical systems using programmable logic controllers. The results show that automatically generated test suites achieve similar code coverage as manually created test suites, but in a fraction of the time (an average improvement of roughly 90%). We also found that the use of an automated test generation tool does not result in better fault detection in terms of mutation score compared to manual testing. Specifically, manual test suites more effectively detect logical, timer and negation type of faults, compared to automatically generated test suites. The results underscore the need to further study how manual testing is performed in industrial practice. We suggest some improvement opportunities for supporting the use of automated test generation tools in testing of industrial control software.


author = {Eduard Paul Enoiu and Adnan Causevic and Daniel Sundmark and Paul Pettersson},
title = {An Industrial Study on Automated Test Generation and Manual Testing of IEC 61131-3 Software},
month = {November},
year = {2016},
publisher = {M{\"a}lardalen Real-Time Research Centre, M{\"a}lardalen University},
url = {}