The preliminary hazard analysis technique is a broad, initial study used in the early stages of system design. It focuses on
- Identifying apparent hazards
- Assessing the severity of potential accidents that could occur involving the hazards
- Identifying safeguards for reducing the risks associated with the hazards.
This technique focuses on identifying weaknesses early in the life of a system, thus saving time and money that might be required for major redesign if the hazards were discovered at a later date.
Characteristics of Preliminary Hazard Analysis
- It relies on brainstorming and expert judgment to assess the significance of hazards and assign a ranking to each situation. This helps in prioritizing recommendations for reducing risks.
- It is typically performed by one or two people who are knowledgeable about the type of activity in question. They participate in review meetings of documentation and field inspections, if applicable.
- It is generally applicable to any activity or system
- It can be used as a high-level analysis early in the life of a process
- It helps generate qualitative descriptions of the hazards related to a process. It also provides a qualitative ranking of the hazardous situations.
- The quality of the evaluation depends on the quality and availability of documentation, the training of the review team leader with respect to the various analysis techniques employed, and the experience of the review teams
Common Uses of Preliminary Hazard Analysis
- It is generally applicable for almost any type of risk assessment application, but focuses predominantly on identifying and classifying hazards rather than evaluating them in detail
- It is most often conducted early in the development of an activity or system, when there is little detailed information or there are few operating procedures. Often a precursor to further risk assessment.
All Systems have its own limitations and Preliminary hazard analysis too has its own limitations. Some of its limitations are as follows
Generally requires additional follow-up analyses. Since it is conducted early in the process and uses preliminary design information, additional analyses are generally required to more fully understand and evaluate hazards and potential accidents identified by the Process Hazard Analysis team.
Quality of the results is highly dependent on the knowledge of the team. At the time of a Process Hazard Analysis, there are few or no fully developed system specifications and little or no detailed design information. Therefore, the risk assessment relies heavily on the knowledge of subject matter experts. If these experts do not participate in the risk assessment, or if the system is a new technology having little or no early operational history, the results of the Process Hazard Analysis will reflect the uncertainty of the team in many of its assessments and assumptions.