Summary
Key results
Early detection of defects and process issues during module testing
Comprehensive test documentation supporting safety certification
Rigorous standards, rising costs, limited resources
Railway systems face some of the strictest safety requirements: every line of code must be tested, documented, and approved per EN 50129, which governs certification for systems that protect passengers’ lives and health.
In practice, this means thousands of module tests and dozens of documentation iterations for each software component. For the client – a global producer of traffic control and digital mobility systems – the challenge was to control cost, timeline, and quality while meeting certification demands.
Distributed testing teams and a lack of centralized standards led to project delays, and each fix required re-verification and re-documentation. The company needed a partner to take end-to-end responsibility for module testing, introduce automation, ensure EN 50129 compliance, and deliver complete certification-grade documentation.
Comprehensive model for testing safety-critical software
Sii Poland assumed full responsibility for module testing of EN 50129–compliant software, establishing a unified quality-assurance model within the client’s environment.
Sii’s team:
- Designed and deployed a VectorCAST-based test environment fully integrated with CI/CD pipelines
- Executed unit and module tests in C, automating scenarios and results reporting
- Implemented tools for defect analysis and reporting to enable rapid issue response and root-cause elimination
- Produced complete, EN 50129–compliant test documentation to support safety certification
- Optimized the testing process to shorten regression cycles and reduce long-term test maintenance costs across the project lifecycle
As a result, the client gained a consistent, predictable testing model that can be replicated across future safety-system projects worldwide.
Higher assurance, lower costs, faster certification
With Sii Poland’s engagement, the client achieved full control over the quality of software used in railway safety systems. The implemented testing model enabled early defect discovery, reducing downstream errors and significantly lowering the cost of fixes.
The automated testing environment shortened regression time and accelerated certification cycles, allowing new functionality to be introduced without risking noncompliance. Comprehensive documentation prepared by Sii experts simplified audits and confirmed adherence to EN 50129, while standardized testing processes made the approach repeatable for subsequent global projects.
Ultimately, the client gained a stable, predictable software quality model that supports the development of innovative traffic control systems and digital rail solutions – improving passenger safety and infrastructure reliability.