Assessing the completeness of safeguard identification in hazards and operability (HAZOP) studies for oil and gas facilities as a quality metric: An Indonesian case study

Abstract Qualitative risk assessments, such as hazard and operability studies (HAZOP), are critical for identifying hazards and implementing risk mitigation strategies in industrial processes. One key yet often overlooked measure of HAZOP quality is the completeness of safeguard identification, which can serve as a practical key result indicator (KRI). This study explores factors influencing safeguard completeness, with a focus on process information accuracy and the operational experience of facilitators. Sixteen HAZOP studies from similar facilities were analyzed by comparing safeguards listed in HAZOP worksheets against those in corresponding piping and instrumentation diagrams (P&IDs). Safeguards were categorized into four types: basic process control systems (BPCS), alarms and manual interventions (AMI), safety instrumented functions (SIFs), and mechanical protections such as pressure safety valves (PSVs). The results indicate that completeness varies significantly depending on facilitator experience and methodological consistency. A positive trend in safeguard identification was also observed in HAZOP revalidations over time. These findings suggest that improving the identification of safeguards enhances the overall effectiveness of qualitative risk assessments and can help establish a standardized metric for evaluating HAZOP study quality.