Human error safety performance

The focus of VR tool for the Risk Assessment is the investigation and integration of Human Factors (HF) aspects and loss or delays on safety-critical tasks using the information and output data from VR experiments, that represent in a real way the accidental scenarios identified. Human Errors and Performance Shaping Factors (PSFs) resulting in accidental scenario can be investigated by means of post-experiments replays and reviews. 

Today, various mathematics and probability concepts are being used to study various types of safety-related problems. For example, probability distributions are used to represent times to human error in performing various types of time-continuous tasks in the area of safety [3-7]. In addition, the Markov method is used to conduct human performance reliability analysis in regard to engineering systems safety [7-9]. 

Dekker, S.W.A. (2002), Reconstructing Human Contributions to Accidents The New View on Human Error and Performance, Journal of Safety Research, 33, 371-385. [PubMed 12404999] [DOI 10.1016/S0022-4375%2802%2900032-4]... 

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. 

This book has been written to show how the science of human factors can be applied at the plant level to significantly improve human performance and reduce human error, thus improving process safety. 

The various PIFs discussed so far provide a basis for the control of human error at the level of the individual. This section will consider various factors related to the performance of the team and the management practices related to safety. 

During the PHEA stage, the analyst has to identify likely human errors and possible ways of error detection and recovery. The PHEA prompts the analyst to examine the main performance-influencing factors (PIFs) (see Chapter 3) which can contribute to critical errors. All the task steps at the bottom level of the HTA are analyzed in turn to identify likely error modes, their potential for recovery, their safety or quality consequences, and the main performance-influencing factors (PIFs) which can give rise to these errors. In this case study, credible errors were found for the majority of the task steps and each error had multiple causes. An analysis of two operations from the HTA is presented to illustrate the outputs of the PHEA. Figure 7.12 shows a PHEA of the two following tasks Receive instructions to pump and Reset system. 

Accountability is the obligation to answer for one s performance with respect to expectations, goals, and objectives. It is an important element of an effective process safety management system. To improve safety, the risk associated with human errors must be reduced. The work situation is the predominant cause of human errors and management has control over the work situation. 

As can be seen, the real cause of most accidents is what might be classified as human errors. Most people have good intentions to perform a function properly, but where shortcuts, easier methods or considerable economic gain opportunities appear or present themselves, human vulnerability usually succumbs to the temptation. Therefore it is prudent in any organization, especially where high risk facilities are operated, to have a system in place to conduct considerable independent checks, inspections, and safety audits of the design and construction of the installation. 

Once again, the designer needs to understand the tasks the user of the display is performing. To increase safety, the displays should reflect what is known about how the information is used and what kinds of displays are likely to cause human error. Even slight changes in the way information is presented can have dramatic effects on performance. 

Allied to Deming s view is the work of Alphonse Chapanis, who was prominent in the field of ergonomics and human factors engineering. Representative of Chapanis writings is The Error-Provocative Situation, a chapter in The Measurement of Safety Performance, by William E. Tarrants (Tarrants, p. 119). 

Alphonse Chapanis is exceptionally well known in ergonomics and human factors engineering circles, and his writings on avoiding the design of work that is error-provocative are often cited. These are excerpts from his chapter titled The Error-Provocative Situation, which is in the book The Measurement of Safety Performance ... 

To extend that idea, this example is quoted from an essay written by Alphonse Chapanis and titled The Error-Provocative Situation A Central Measurement Problem in Human Factors Engineering. It is in the book The Measurement of Safety Performance by Dr. William E. Tarrants. 

All relevant personnel should be made aware of the importance to safety of the tasks that they perform for MS I and of the potential consequences for safety of technical, procedural or human errors. Experience of faults and hazards caused by errors in MS I procedures and practices at the nuclear power plant concerned or at other plants, and in other potentially hazardous industries, should be reviewed and incorporated into personnel training programmes as appropriate. 

People and the jobs they do play an important safety role. Nowhere is this made more clear than in the study of aviation disasters, where, in more than two out of three cases, accident investigators are driven to conclude that human error played a major role (Edwards, 1988). These errors are not usually due to sudden illness, suicidal tendencies, wilful neglect or lack of basic abilities. More typically, they arise from temporary breakdown in skilled performance because, in many instances, system designers and managers have paid insufficient attention to human characteristics and skills, or not properly accounted for enviromnental stressors, workload and other reasonably foreseeable distractions. 

While human reliabihty analysis (HRA) has been well established and integrated into safety analysis in other industries (nuclear, aviation...) its application to healthcare is limited (Lyons, et.al. 2004). HRA studies human operator performance in the context of a specific task enviromnent. It is often focused on estimating the probability of human error, and how this probability might increase or decrease when coupled with various performance shaping factors. 

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