Human errors analysis

Rasmussen, J. 1979. Notes on human error analysis and prediction. In G. Apostalakis and G. Volta (Eds.), Synthesis and Analysis Methods for Safety and Reliability Studies, Plenum, New York. 

ATHEA A Technique for Human Error Analysis NUREG/CR-6350... 

In addition to their descriptive fimctions, TA techniques provide a wide variety of information about the task that can be useful for error prediction and prevention. To this extent, there is a considerable overlap between Task Analysis and Human Error Analysis (HEA) techniques described later in this chapter. HEA methods generally take the result of TA as their starting point and examine what aspects of the task can contribute to human error, hr the context of human error reduction in the CPI, a combination of TA and HEA methods will be the most suitable form of analysis. 

The application of human error analysis (HEA) techniques is to predict possible errors that may occur in a task. The next stage of error analysis is to identify error recovery possibilities implicit within the task, and to specify possible... 

Predictive human error analysis can be performed manually or by means of a computer software package. Three types of analysis are possible within PHEA. 

FIGURE 4.17. Documentation of the Results of Human Error Analysis... 

The intention of this chapter has been to provide an overview of analytical methods for predicting and reducing human error in CPI tasks. The data collection methods and ergonomics checklists are useful in generating operational data about the characteristics of the task, the skills and experience required, and the interaction between the worker and the task. Task analysis methods organize these data into a coherent description or representation of the objectives and work methods required to carry out the task. This task description is subsequently utilized in human error analysis methods to examine the possible errors that can occur during a task. 

Predictive human error analysis (PHEA) is the process via which specific errors associated with tasks or task steps are predicted. The process also considers how these predicted errors might be recovered before they have negative consequences. The inputs to the process are the task structure and plans, as defined by the task analysis, and the results of the PIF analysis. The basic procedure of the PHEA is as follows ... 

A. Perform Detailed Predictive Human Error Analysis (PHEA)... 

The error reduction analysis concludes one complete cycle of the qualitative human error analysis component of the methodology set out in Figure 5.4. The analyst then decides if it is appropriate to perform a more detailed analysis on any of the operations considered at the current level. As a result of this process, operations 3.2 Monitor tanker following operation, 4.1 Stop filling operation, 4.2 Disconnect tanker, and 4.4 Secure tanker are analyzed in more detail (see Figure 5.6). 

The qualitative human error analysis stages described above are applied to the task steps in subtask 3.2. Examples of the results of this analysis are shown in Figure 5.8. The corresponding error-reduction strategies are shown in Figure 5.9. 

This section illustrates how the techniques described in Chapter 4 can be used to develop a procedure for the job of the top floor operator in the batch plant considered earlier. Two techniques are illustrated (i) a hierarchical task analysis (HTA) of the job, and (ii) a predictive human error analysis (PHEA) of the operations involved. HTA provides a description of how the job is actually done while PHEA identifies critical errors which can have an impact on the system in terms of safety or quality. The basic structure of the procedure is derived from the HTA which specifies in increasing detail the goals to be achieved. To emphasize critical task steps, various warnings and cautions can be issued based on the likely errors and recovery points generated by the PHEA. 

One of the most noticeable ergonomic deficiencies in both control rooms was the number of panels that had to be scanned and monitored during the scenarios, and the number of rapid actions required at opposite ends of the control room. The need for virtually simultaneous actions and movements would have been discovered and resolved in the design stage had a task analysis and human error analysis been carried out on an emergency operation. 

Task Analysis and Error Analysis of the Blowdown Operation Task analysis was carried out in order to organize all the performance data about the way that workers process information, the nature of the emergency and the way that decisions are made. Figure 7.20 shows a tabular task analysis of the workers response to a significant unignited gas leak in MSM. The analysis was a combination of a tabular HTA and a CADET analysis (see Chapter 4). Human error analysis identified the major human failure modes which could affect time to blowdown (see Table 7.2). 

Kirwan, B. (1990). Human Error Analysis. In J. R. Wilson E. N. Corlett (Eds.). Evaluation of Human Work, a Practical Ergonomics Methodology. Washington, DC Taylor and Francis. 

FIGURE 5.8 Results of Predictive Human Error Analysis. 219... 

There arc oilier methods of hazard identification. A "wliat-if analysis presents certain questions about a particular hazard and then tries to find llie possible consequences of that hazard. The human-error analysis identifies potential human errors that will lead to an accident. They can be used in conjunction with llic two previously described methods.. ... 

Human error analysis This method is used to identify the parts and the procedures of a process that have a higher than normal probability of human error. Control panel layout is an excellent application for human error analysis because a control panel can be designed in such a fashion that human error is inevitable. 

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