Glossary · Requirements and interfaces
Performance requirement
German: Leistungsanforderung
In systems engineering, a performance requirement states how well a system or element must perform a function, expressed as a measurable quantity with limits, such as throughput, cycle time, accuracy, response time or availability.
- Systems engineering
In one sentence
A performance requirement states how well a function must be performed, with measurable limits such as cycle time, accuracy or throughput.
Example
The palletizer must handle at least 20 cases per minute with a positioning accuracy of ±2 mm.
How it applies
- Engineering: Performance requirements need a measurable value, unit, conditions and a Verification method; "fast" or "high accuracy" cannot be verified.
- Testing: They are typically verified by test or analysis under defined load, and often drive acceptance criteria in FAT and SAT.
- Documentation: Stated performance values in brochures and manuals should match the verified requirement and its conditions; the documentation team should flag marketing values that go beyond it.
- Supply chain: When a performance requirement is split across subsystems (for example cycle time across robot, conveyor and vision), each supplier needs its own share, and the margin between them should be documented.
Performance requirement vs. Performance Level
A performance requirement concerns functional performance. The Performance Level (PL) of ISO 13849-1 is a measure of the reliability of a safety function and has nothing to do with speed or throughput.