Managing Human Error Potential

The HAZOP technique can be used to identity human error potential. From a practical point of view, human error and its consequences can occur at all levels of a management structure as well as in the operation of a particular plant or process. Carried out correctly, Technica54 states that a HAZOP study will identify at least 70-75 percent of potential operational and safety problems associated with a particular design process, including human error. 

To avoid hazard-related incidents resulting in serious injuries, human error potentials must be addressed at the cultural, organizational, management systems, design, and engineering levels, and with respect to the work methods prescribed. 

To be able to systematically identify opportunities for reducing human error, it is useful to ask the question, What is human error One definition is that human error is an inappropriate or undesirable human decision or behavior that reduces, or has the potential for reducing safety or system performance (Rasmusssen 1979). There is a tendency to view errors as operator errors. However, the error may result from inadequate management, design, or maintenance of the system. This broader view which encompasses the whole system can help provide opportunities for instituting measures to reduce the likelihood of errors. 

Measures to reduce human error are often implemented at an existing plant, rather than during the design process. The decision to conduct an evaluation of the factors that can affect error potential at an existing plant may be taken for several reasons. If human errors are giving rise to unacceptable safety, quality or production problems, plant management, with the assistance of the workforce, may wish to carry out a general evaluahon or audit of the plant in order to identify the direct causes of these problems. 

Inspection of the HRA event tree reveals that the dominant human error is Error A the operator failing to isolate the propane valves first. The other potential human errors are factors only if a propane isolation valve sticks open. Based on these qualitative results alone, a manager rrught decide to periodically train operators on the proper procedure for isolating a failed condenser and to ensure that operators are aware of the potential hazards. The manager might... 

This is a situation where a plant appears to be operating successfully, without a major human error problem. However, management are interested in assessing the systems in the plant from the point of view of minimizing the error potential. This type of exercise is particularly relevant for plants dealing with substances or processes with high hazard potential, for example, in terms of... 

Management must modify the culture and develop human factors awareness in the hazard identification teams so that they will be capable of identifying the potential for human error. A good practice is to involve operators in the hazard identification team. 

Systematic errors can occur anywhere in the design and implementation process or during the operational life of an SIS device. These errors put the SIS on the path to failure in spite of the design elements incorporated to achieve robust hardware and software systems. Systematic errors are minimized using work processes that address potential human errors in the SIS design and management (e.g., programming errors or hardware specification errors). 

This paper deals with the classification of an error type and the characteristics of human errors by each error type for the test and maintenance failures that have led to implanned reactor trips in Korean nuclear power plants. The classification of hmnan errors was basically performed on the taxonomy of Reason s basic error types (Reason 1990). Characteristics of the test and maintenance errors include the major contributing factors or error modes, and predictivity or identifiabil-ity of a potential erroneous action from the viewpoint of a human error prevention or management. 

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