Conducting Human Factors Safety Analysis

The objective of human factors safety analysis is to identify and correct human error situations that could lead to significant hazards. The analysis can be either qualitative or quantitative, depending on the level of detail desired and what the consequences are of a person making a mistake. The steps of a human factors safety analysis are as follows  

Step 1 Describe the system goals and functions. Then define the system hazards of interest. These are system functions that may be influenced by human errors. Use one of the other safety tools (e.g., HAZOP) described earlier. 

Step 2 List and analyze the related human operations. A qualitative tool—task analysis— will be employed. It analyzes how the task is performed and what types of aids are needed to support performance. 

Step 3 Analyze the human errors. Look at how the task can fail, what errors can occur, and how the system can recover from them. 

Step 4 Screen the identified errors and decide which ones are worth quantifying. 

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The design review, a formal and documented review of a system design, is conducted by a committee of senior company personnel who are experienced in various pertinent aspects of product design, reliability, manufacturing, materials, stress analysis, human factors, safety, logistics, maintenance, and so on. Tlie design review extends over aU phases of product development, fiom conception to production. In each phase, previous work is u( ted, and the review is based on current information. 

During Phase I, the project team will conduct high-level hazards analyses, probably using some form of Major Hazards Screening. The team will be looking for killer problems that are so serious that the project will have to be canceled. The analysis will not consider details on design or the occupational safety and human factors issues discussed in the previous chapters. 

The HazOp study differs from the FMEA and ETBA in that some suggest that the best time to conduct a HazOp is when the design is fairly firm (Goldwaite 1987). Conventional system safety wisdom dictates that the system safety effort be as far upstream as practical, with a facility preliminary hazard analysis developed as part of the initial design effort and completed by the 35% stage. Also, a HazOp study tends to include human factors and operator errors whereas a traditional FMEA or ETBA normally examines hardware failures only. 

Retain a firm with comprehensive PSM expertise. This firm should be an expert in pressure relief systems, safety instrumented systems, human factor analysis, etc. The firm must perform process safety audits, to conduct a refinery-wide comprehensive audit and analysis of the company s PSM systems [22]. 

This paper describes the development of a tool set for incident investigation that incorporates the use of a suite of tools to assess human error, violations and safety culture as an integral part of the investigation. This approach helps to overcome issues associated with a delay in the investigation of human factors that can occur if such techniques are applied in a stand-alone context. This approach also has the benefit of collecting data on the human aspects of safety as a whole, rather than independently conducting several forms of analysis. This allows the complex relationships between people, the organisation, the environment and the task to be captured. 

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