Human Error Analysis Techniques

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 

APPLICATIONS HTA OAET DA CHARTS OSDS SFCS CADET IMAS 

FIGURE 4.15. How to Use Various TA Methods in Human Factors Application 

---

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. 

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. 

Human Error Analysis is used to identify those conditions at which errors made by personnel are most likely to occur. It is often possible to reduce the likelihood of such errors by considering human factors in the design [262-264]. A few examples are presented below to illustrate this technique ... 

An evaluation method to determine the probability that a system-required human action, task, or job will be successfully completed within the required time period and that no extraneous human actions detrimental to system performance will be performed. It provides quantitative estimates of human error potential due to work environment, human-machine interfaces, and required operational tasks. Such an evaluation can identify weaknesses in operator interfaces with a system, quantitatively demonstrate improvements in human interfaces, improve system evaluations by including human elements, and demonstrate quantitative prediction of human behavior. See also ATHEANA (A Technique for Human Error Analysis) Human Error Analysis. 

ATHENA A technique for human error analysis. ATHENA is one HRA method which has been developed to improve the state-of-the-art in HRA, especially with respect to how realistically HRA can represent the kinds of human behaviors seen in accidents and near-miss events. It requires a good amount of resources. ATHENA approach incorporates the current understanding of why errors occur, based on the work of earlier pioneers, and substantiated by reviews of a number of significant accidents. It has been developed for mainly for nuclear application, but now it is used in generic manner. 

Human Error Analysis encompasses a number of different techniques. All should relate tasks to the skills required to perform those tasks. 

ABSTRACT Permit To Work (FTW) is a means of safety system to coordinate different work activities. However, it may be susceptible for human error. The purpose of this study was identification and analysis of human errors in PTW system using Predictive Human Error Analysis (PHEA) technique. The most important identified errors were inadequate isolation of process equipments, inadequate labelling of equipment, and delay in starting the work after issue the work permit, improper gas testing, inadequate site preparation measures etc. Finally for preventing and recovering from the identified errors, site work permit form and its procedure was revised. 

In the second stage. Predictive Human Error Analysis (PHEA) technique was used for... 

On the other hand, some contemporary approaches to HRA such as A Technique for Human Error Analysis ATHEANA (Barriere et al. 2000), the Connectionism Assessment of Human Rehabihty (CAHR) based on Strater (2000) and the Cognitive Rehabihty and Error Analysis Method (CREAM) by HoUnagel (1998) were developed around the principle that the fundamental element is, in fact, the context in which the task is performed, reducing previous emphasis on the task characteristics per se and on a hypothetical inherent human error probabihty. 

A Technique for Human Event ANAlysis (ATHEANA) was developed by the nuclear industry due to a perceived need for a human error analysis tool that more closely modeled actual operational events and which put a stronger focus on contextual factors. The quantification is based around three calculations. Eirst, calculating the probability of an Error Eorcing Condition (EEC i.e. the probability that the plant will be in a state which may induce an error). This is determined by a combination of plant conditions and PSEs. Second, the probability of an Unsafe Action (UA). And third, the probability of not recovering from the initial UA. This third area incorporates the possibility of alarms and/or feedback to the operator allowing them to correct the UA. 

Second generation methods which were first applied in 1990, are based on a cognitive model that is more appropriate to explain human behavior. The focus shifted to the cognitive aspects of humans, the causes of errors rather than their frequency, the study of the interaction of the factors that increase the probability of error, and the interdependencies of the PSF (Fehce Petrillo, 2011). The most representative tools are Standardized Plant Analysis Risk-Human reliability analysis method (SPAR-H), German et al. (2005) A Technique for Human Error ANAlysis (ATHEANA), NUREG-1624 (2000) as well as Cognitive Reliability and Error Analysis Method (CREAM), Hollnagel (1998). 

In the process of risk and human reliability assessment, there are various methods to be used, such as Cognitive Reliability and Error Analysis Model (CREAM), A Technique for Human Error Analysis (ATHENA), and Technique for Human Error Rate Prediction (THERP). 

Chapter 9 describes a framework for the identification and quantification of human error in fishing vessel operation, following a brief review of human error assessment techniques. This framework ranks the impact of human error and further integrates the available risk control options into the analysis. The approach uses Analytical Hierarchy Processing (AHP) theory to rank the preference of each control option. The advantages of employing the AHP technique are discussed and the integration of such a technique within the FSA framework is described. 

Human error probabilities can also be estimated using methodologies and techniques originally developed in the nuclear industry. A number of different models are available (Swain, Comparative Evaluation of Methods for Human Reliability Analysis, GRS Project RS 688, 1988). This estimation process should be done with great care, as many factors can affect the reliability of the estimates. Methodologies using expert opinion to obtain failure rate and probability estimates have also been used where there is sparse or inappropriate data. 

The various analytical methods for predicting and reducing human error can be assigned to four groups or sections. In order to make a start on any form of analysis or prediction of human error, it is obviously necessary to gather information. The first section therefore describes a number of techniques that can be applied to acquire data about what the worker does, or what happened in an accident. 

Task analysis is a fundamental methodology in the assessment and reduction of human error. A very wide variety of different task analysis methods exist, and it would be impracticable to describe all these techniques in this chapter. Instead, the intention is to describe representative methodologies applicable to different types of task. Techniques that have actually been applied in the CPI will be emphasized. An extended review of task analysis techniques is available in Kirwan and Ainsworth (1993). 

The other main application area for predictive error analysis is in chemical process quantitative risk assessment (CPQRA) as a means of identifying human errors with significant risk consequences. In most cases, the generation of error modes in CPQRA is a somewhat unsystematic process, since it only considers errors that involve the failure to perform some pre-specified function, usually in an emergency (e.g., responding to an alarm within a time interval). The fact that errors of commission can arise as a result of diagnostic failures, or that poor interface design or procedures can also induce errors is rarely considered as part of CPQRA. However, this may be due to the fact that HEA techniques are not widely known in the chemical industry. The application of error analysis in CPQRA will be discussed further in Chapter 5. 

In addition, the chapter will provide an overview of htunan reliability quantification techniques, and the relationship between these techniques and qualitative modeling. The chapter will also describe how human reliability is integrated into chemical process quantitative risk assessment (CPQRA). Both qualitative and quantitative techniques will be integrated within a framework called SPEAR (System for Predictive Error Analysis and Reduction). 

Qualitative human error prediction is the most important aspect of assessing and reducing the human contribution to risk. For this reason, it will be described in some detail in this section. The qualitative analysis performed in SPEAR involves the following techniques ... 

If the results of the qualitative analysis are to be used as a starting-point for quantification, they need to be represented in an appropriate form. The form of representation can be a fault tree, as shown in Figure 5.2, or an event tree (see Bellamy et al., 1986). The event tree has traditionally been used to model simple tasks at the level of individual task steps, for example in the THERP (Technique for Human Error Rate Prediction) method for human reliability... 

---