Scope of the initial investigation was complete site SIS infrastructure including the hot and cold sections of plant. Pared down focus final report included twenty (20) critical interlocks associated with one of the refrigeration compressors. The SIS Key Performance Indicators (KPI) that were felt to convey �safety culture� included: SIF demand rate, SIF failure on demand, SIF failure in proof test, online instrument health, instrument failure rates, bypass durations, and repair time after failure diagnostic. Consultant provided expert instrument background, investigation, failure insights, and a conclusive path forward.