How do you assess and document systematic capability for SIS components and software?

Systematic capability assessment per IEC 61508: for hardware - demonstrate prior use (sufficient operating history without systematic failures) or compliance with IEC 61508-2 development requirements (design reviews, FMEA, proven design techniques). For software - development lifecycle compliance (IEC 61508-3), coding standards, verification and validation, independence of development and testing, and use of certified tools. Document: design documentation, V&V reports, test coverage analysis, configuration management records, and competency evidence. Systematic capability must match or exceed target SIL. Complex devices (Type B, software-based) require full lifecycle compliance; simple devices can use proven-in-use route. Maintain evidence package for audit.