Opinion: What should be considered when planning system integration testing for a new railway line?
- By Ilse Vermeij, Rail Product Manager Testing, Ricardo
System integration testing is an important part of verifying whether a complex system has been implemented correctly. I think the V-model is still the best way to illustrate the process (see below).
For new rail infrastructure projects of any size – whether a new urban transit route or a high-speed network – system integration testing will need to take place at the following levels :
- Test all subsystems work together as specified.
- Check that the infrastructure is operating as intended, with vehicles running.
Key stages of a test program
Before starting the program, all subsystems must be tested at the factory (FAT) and on site, after installation (SAT).
System integration testing should then be undertaken – with and without the vehicle – to test the performance of the infrastructure against the original design intentions.
After integration testing is complete, testing in trial operations can focus on operational performance, including maintenance and security (evacuation and access to emergency services, for example).
Since these different aspects of testing are part of a new infrastructure project, it is important that testing is considered an integral part of the design and construction process, with the various stakeholders being centrally managed.
More importantly, testing should never be an afterthought – something to be inserted right at the end of the project – as this risks identifying issues only to find that the build process is too far along for issues to arise. be easily corrected. .
When testing is considered in the early stages of the project, potentially critical systems can be identified and advanced in the schedule so that their integration can be tested when the time is right.
If it is not possible to test critical systems early enough in the final infrastructure environment, testing with a hardware or software digital twin should be considered.
Additionally, requirements at all levels should ideally be managed centrally, allowing the team responsible for testing, verification, and validation to create an optimal test plan.
What do we mean by “optimal test”?
“Optimal testing” means that the infrastructure has successfully gone live without “excessive testing”, which means that we spend time and resources performing tests that, in hindsight, you realize are not were not necessary.
To create an optimal test plan, you need experience in systems integration testing and stakeholder involvement that can help identify the most critical aspects of the infrastructure. Ultimately, the goal is to determine the smartest test combinations, so that unnecessary tests are removed from the program and the total effort is reduced.
Centralized requirements management is essential to identify the most optimal combinations. This helps the test team to create an overview of all the requirements ready to be tested and to monitor the tests that have yet to be run.
Utrecht tram – Optimal tests in action
An example of the effectiveness of this approach was demonstrated in the program we designed for the modernization of a busy tram line here in Utrecht during the summer of 2020.
This project saw the introduction of a new fleet of low-floor vehicles along a redeveloped route. But in this case, preparations with the infrastructure contractor, BAM, started more than a year in advance, which allowed us to agree on a definitive program of more than 100 individual tests – across a range of pitches, speeds and vehicle configurations – which satisfied BAM’s safety and contractual requirements.
With such a planning delay, the program was completed on schedule, allowing the new infrastructure to enter service without failure. The optimized test program is considered an important factor in the success of the whole project.
Click here to see the full case study of our test work on the Utrecht tram.
This article was originally published by Ricardo Rail.