Functional Performance Testing and Test Procedures
Functional performance testing (FPT) demonstrates that systems and assemblies operate interactively to meet the OPR. Tests are written before construction, reviewed by the team, and executed against documented procedures with pass/fail criteria, prerequisites, instrumentation, and data-recording requirements.
Test design principles: test the system, not just components; test modes (normal, emergency, seasonal, part-load); test sequences and interlocks; and test under conditions that reveal failure. Where full-load conditions cannot be created, use simulation or trend data with documented rationale. The candidate must know that FPT is witnessed by the CxA, with the contractor operating the equipment and the designer available to interpret intent.
Traps: (1) accepting a test with no documented prerequisites or pass criteria; (2) testing components in isolation and calling it system verification; (3) skipping failure-mode and interlock tests; (4) failing to record actual readings and trend data; (5) retesting without documenting the deficiency and correction. Also know the difference between a test procedure (the script) and a test record (the evidence).
Rule of thumb: a well-written test can be executed by someone who did not write it - if it needs verbal explanation, it is incomplete. Worked example: for an air handler, the procedure lists prerequisites (filters installed, TAB complete), steps (command to occupied mode, verify fan speed, damper position, static pressure setpoint control), expected results, and a data table for recorded values.