HAZOPstudier

HAZOPstudier, or Hazard and Operability Studies, are structured, systematic reviews used to identify hazards and operability problems in industrial process systems. They are typically applied during design, modification, or operation of chemical, petrochemical, pharmaceutical, and energy processes to enhance safety and reliability.

The method is team-based and cross-disciplinary. A HAZOP study is conducted on a process or piping and instrumentation diagram (P&ID) by dividing the system into nodes (sections) and evaluating each parameter (flow, temperature, pressure, composition, level, phase) against design intent. Guided by standard guide words (for example, no flow, low flow, high temperature, reverse flow), the team considers potential deviations, their causes, and their potential consequences. Safeguards such as alarms, interlocks, relief systems, and protective equipment are examined, and recommendations are recorded.

Typical steps include defining scope and objectives; assembling a motivated, diverse team; gathering design data; conducting structured brainstorming sessions; documenting deviations, causes, consequences, existing protections, and actions; assigning ownership and target dates; drafting a HAZOP report and tracking actions. IEC 61882 provides guidance on guide words and application.

Benefits of HAZOPstudier include early hazard identification, improved safety and control system design, risk reduction, and better communication among engineering staff. Limitations involve the time and resources required, potential facilitator bias, dependence on input data quality, and the possibility of missing low-probability events. Applications span project phases from concept to detailed design and into modifications, often complemented by What-If analyses and risk assessment tools such as Layer of Protection Analysis (LOPA).