One of the best practices for identifying the risk associated with a system or operating process is to conduct a Hazard Operability Study (HAZOP). HAZOP is a systematic process that allows you to evaluate a new or existing complex systems procedure or process and identifies areas of possible failure so that you can implement the proper preventative and mitigation measures necessary to reduce risk exposure to personnel or equipment.
HAZOP is used to assess the design of a system and ensures the system can operate within specification and physical/operational environments. HAZOP can also be used to assess operational controls for start-up, shutdown and operation procedures.
To complete a HAZOP study, a four-phase methodology is generally used. First is the definition phase where the HAZOP scope and objectives are defined and the HAZOP committee or team is selected. Once a team is in place, responsibilities of each team member are assigned. It is important to make sure the HAZOP team is represented by a variety of subject matter experts who understand how the system being reviewed works and have a positive mindset towards improving the process.
The next phase is the preparation phase. In this stage, the HAZOP team plans the study by defining a timeframe for the study and then sets a schedule. During the preparation phase, the team will also agree on how the study will be recorded and all of the existing data is gathered for the system that is going to be reviewed.
Phase three of the HAZOP study is the examination process. During the examination process, the system being analyzed is broken into parts. Using guidewords for each element helps identify the deviations in the system. Guidewords are important as they bring focus to the study and promote constructive conversation and brainstorming sessions. The HAZOP team will also identify the potential causes of and consequences of system failures that have been identified. Once the potential system failures have been identified the HAZOP team looks for possible prevention and mitigation measures and agrees on action items. This process is repeated for each element of the system that is being analyzed in the HAZOP study.
The fourth and final phase of the HAZOP study consists of the team producing a record of examination, signing off on required documents, following up on any remaining action items and if necessary, re-examining parts of the system where questions still remain. Finally, the team will produce a final report and present their findings to the proper levels of management.
Analyze, isolate, count or are related to human performance. HAZOP studies also do not require that you rate the probability or severity of failures so you are not forced to prioritize action items based on how they fall into a risk matrix. The downside to HAZOP studies is that they are system and process exclusive and do not test the interaction between different systems and processes.