What is a Procedure HAZOP?
In this article:
A Hazard and Operability study (HAZOP) is a systematic, detailed brainstorming methodology for identifying and analysing potential risks within a system, subsystem, or project. It is one of the most well-known and applied methodologies within risk management. The most common application for HAZOP studies are for industrial processes within sectors such as oil and gas, the chemical industry and petrochemicals. Another application is for procedures, which is the type of HAZOP that is in focus in this article. Examples of procedures include performing a Light Well Intervention, lifting operations, mooring an FPSO to the quay, or changing a piece of equipment in a process. The overall objective of the risk assessment is to identify potential deviations and evaluate the risks, suggest appropriate safeguards, and thereby reduce the probability of an unwanted event and/or mitigate the severity of the consequences.
Procedure HAZOP method
The method used for Procedure HAZOPs is very similar to the more widely known method for Process HAZOPs (which is explained thoroughly in this other article about HAZOP studies). The method for Procedure HAZOPs is described in the following sections.
Preparations
The planning and preparation phase of the Procedure HAZOP is crucial for ensuring the quality of the study. The scope must be agreed upon and fully understood by all participants. This includes the duration of the workshop, the agenda, methodology, guidewords and parameters, the procedure to be assessed, and the division of nodes. Typically, the division of nodes is based on main segments/steps in the procedure. Subject to the specific procedure to be covered, pre-population of the worksheet can be considered. It should be noted that a Procedure HAZOP will normally focus on unique hazards and concerns associated with the procedure and not on the inherent risk picture and management found at any industrial site.
HAZOP Team members
To capture different aspects of the procedure, individuals from various disciplines should be invited to participate in the Procedure HAZOP workshop, ensuring a multidisciplinary approach. Required expertise may include technical safety, operations, project lead, technical specialists, maintenance and other expertise relevant for the scope. Additionally, a facilitator and scribe are utilized to ensure the structure, quality, and efficiency of the study, as well as to document the workshop.
Procedure HAZOP workshop
The workshop is the central component of the Procedure HAZOP study. This is where hazardous scenarios are identified and recommendations for further risk-reducing measures are proposed. The workshop is structured around nodes and parameters/guidewords.
Parameters & guidewords
Predefined parameters and guidewords are utilized to inspire participants in identifying potential deviations that could lead to hazardous scenarios arising from the operation following the procedure. These guidewords also provide structure to the brainstorming and analysis process. For Procedure HAZOPs, parameters and guidewords relevant to the procedure are employed. Some examples of these are listed below:
Step/action omitted, incomplete, too early/late, too short/long, too little/much, too fast slow, executed wrongly
Access - issues regarding the access making the operation harder to perform
Physical environment - issues related to temperature, lighting, noise, ventilation that could make the operation harder to perform
Weather - issues regarding the weather, unclear weather restrictions or unexpected deterioration of weather affecting the feasibility of the operation
Impact - issues related to impact between objects when performing the operation
Position - issues related to if there are equipment or objects that must be in certain positions during the operation
Drop - related to drop of objects from higher level
Power - issues with the power supply impacting the operation
Instruments - malfunction or lack of instruments during the operation
Communication - issues regarding the communication and the communication equipment
Movement - issues regarding unwanted movement of objects
Stuck - issues relates to objects/equipment getting stuck during the operation
Rupture - issues relating to rupture of critical equipment during the operation
Barriers - issues regarding insufficient barriers in connection to the operation
Tension - issues relating to high tension in wires or similar, which in case of rupture releases lots of energy
Experience - regarding if the procedure has been used before or is new
Environmental - issues regarding potential environmental pollution
Which words to be used may vary slightly depending on the procedure - the guidewords are selected to be relevant for the specific procedure. It is important to note that using too many guidewords can make the workshop tedious, while too few can result in missing possible deviations leading to hazardous scenarios.
Cause, consequence, safeguards and recommendations
For each hazardous scenario identified, the possible causes, worst credible consequences, and existing safeguards to prevent or mitigate the scenario are assessed. The team then determines whether further risk reduction measures are necessary. These measures can either decrease the likelihood of an incident or decrease the severity of the consequences if the incident occurs. If additional risk reduction is required, one or more recommendations are proposed, and a responsible company or individual is designated. This designated party is accountable for ensuring the implementation and closure of the recommendation.
Risk ranking
Risk ranking is sometimes conducted for each scenario, though it is not always a mandatory component of the study. The ranking is based on a combination of the estimated frequency or probability of a scenario occurring and the severity of its consequences. When included, the ranking is used to semi-quantitatively (using numbers) or qualitatively (using words) assess the risk and prioritize scenarios that require additional or improved safeguards. This ranking can be performed either before or after the implementation of new safeguards, or both.
Recording of the Procedure HAZOP workshop
To ensure no important information is missed during the workshop, the causes, consequences, safeguards, recommendations, responsible parties, risk ranking estimates, and other comments are documented according to a pre-agreed structure of nodes, parameters, and guidewords.
In some projects, only potential scenarios where recommendations are identified are recorded, while scenarios not requiring further action are omitted. Other projects may require all scenarios with credible deviations to be recorded, regardless of whether they result in recommendations. In some cases, a “full recording” approach is applied, meaning all discussed scenarios are documented, irrespective of the significance of the potential deviation.
The recording is crucial for tracing the discussions and understanding the agreements made during the workshop. It also serves as a valuable resource for individuals who were not present, enabling them to comprehend the recommendations and the context in which they were made. Therefore, it is essential to ensure that the formulations are detailed and clear enough for those outside the workshop to understand.
How to ensure the quality of the Procedure HAZOP
Key factors for ensuring a high quality Procedure HAZOP are:
Well prepared participants - Ensuring participants are well-prepared keeps discussions within the Procedure HAZOP scope and prevents digressions into background information. Thorough preparation is crucial for the quality of discussions, which form the foundation for the study’s findings.
Experienced and multidisciplinary team - A team comprising various disciplines brings diverse perspectives, essential for covering all critical aspects of the procedure under review. Multiple disciplines are vital to ensure coverage of all the important angles of the procedure that is HAZOPed.
Adherence to structure - Maintaining a systematic approach ensures no parameter or guideword is overlooked, thereby preventing potential hazards from being missed. Selecting appropriate guidewords and parameters is also crucial to keep discussions relevant, useful, and to make the workshop efficient.
Clear and detailed recording - Ensuring that the recording of the workshop is clear and detailed is essential for workshop-external stakeholders to understand the recommendations and the rationale behind them. This clarity is also important for future look-backs to the Procedure HAZOP study.
%20(1).png)
