Identification tasks analyses

If the hierarchical means-ends analysis synthesis procedure is applied to the methyl acetate problem, the task identification, task integration, and equipment design stages are kept completely separate. Following the property-difference hierarchy, an identity-changing reaction task (Task A) is identified first, as before. When examining the differences between the result of this reaction task application and the product methyl acetate and by-product water destinations,... 

The Type A investigation of a sodium potassium (NaK) accident that occurred at the Y-12 plant on December 8, 1999, identified a lack of understanding of the hazard from NaK and its reactive byproducts as one of the root causes of the accident. The investigation found that personnel involved in planning the task, the safety documentation for the facility, the procedure for the task, and the procedures supporting hazard identification and analysis did not address the complete NaK hazard. The investigation also determined that detailed hazard identification data supported by accident analysis and appropriate control information was readily available. 

Implementation of sound design practices, including the use of requirements definition, user profile development, tasks analysis, and task allocation Setting usability objectives that focus around effectiveness, intuitiveness, and subjective perception Iterative usability evaluation Identification of users mental models Identification of appropriate metaphors... 

Attend at least two 8-hour safety training courses/seminars per year. (Examples include Modern Safety Management, Accident Investigation, Critical Task Identification and Analysis, Risk Assessment, Accredited Auditors.)... 

The goal of human error quantification is to produce error probabilities, building on task analysis and error identification techniques to provide a probabilistic risk assessment (PRA). This provides numerical estimates of error likelihood and of the probability of overall likelihood of system breakdown. Quantification of error is the most difficult aspect of HRA, often heavily reliant on expert judgement, rather than the more rigorous approach of actual observation and recording of error frequencies. Such techniques are little used in healthcare but have been successfully applied to anaesthesia (Pate-Cornell and Bea, 1992). Nevertheless, some hospital tasks, such as blood transfusion, are highly structured and the quantification of errors probabilities would seem to be eminently feasible (Lyons et al, 2004). 

The systematic identification and evaluation of the possible errors that may be made by individuals. Various analysis methods are used such as Task Analysis, Job Safety Analysis, and Root Cause Map. See also ATHEANA (A Teehnique for Human Error Analysis) Job Safety Analysis (JSA) Root Cause Map (RCM). 

The job safety analysis (JSA) [also referred to as the job hazard analysis (JHA)], which is a more simplified form of task analysis, has been a longstanding tool for task and function analysis. JSA has been available and utilized in general industry for many years by the industrial safety community. However, many practitioners do not understand or are simply unfamiliar with the connection between the JSA and the system safety tasks of hazard identification and analysis. It has even been suggested by some in the profession that the JSA itself is a type of oversimplified system safety analysis and, if performed earlier in the job development phase, could be used as the basis of a preliminary hazard analysis for a specific task or set of tasks. However, because JSA is often (if improperly) used to analyze a function only after it has been implemented, much of the data is not factored into the system safety process. The primary purpose of the JSA is to uncover inherent or potential hazards that may be encountered in the work environment. This basic definition is not unlike that previously discussed regarding the various system safety analyses. The primary difference between the two is subtle but important and is found in the end-use purpose of the JSA. Once the job or task is completed, the JSA is usually used as an effective tool for training and orienting the new employee into the work environment. The JSA presents a verbal picture of a specific job. 

Figure 4.1 shows a typical job safety analysis form that can be utilized by any organization wishing to capitalize on this basic method of hazard identification and analysis. It should be noted again that it is most ideal if the task supervisor completes each JSA for those operations under his/her direction. This makes sense since... 

A plan may begin with hazard identification and analysis methods or it may be the consequence of such methods that offers recommendations for improvement. A plan includes at least three components (1) a list of actions or tasks and who will complete them (2) a schedule for their implementation and (3) an estimate of costs. Costs may include human resources, as well as monetary resources. 

Part of the difficulty of task analysis, or, more accurately, knowledge identification, is that the relation between sMls and knowledge, between principles and procedures, is obscure. The skills of a particular domain are relatively easy to identify. A domain of knowledge is typically associated with one or more canonical problem types, and we recognize experts in the domain by the fact that they have the skills required to solve those problem types. The canonical task in arithmetic is to perform calculations, the canonical tasks of medicine are to diagnose and to apply treatment, and so on. An Artificial Intelligence system that can solve a canonical problem is often a decent first approximation to how experts solve that problem. 

A CTA can concentrate initially on the identification and analysis of the relationships between system hazards and safety-related operational tasks. This analysis will enable both the PHA and TAs to be checked for consistency, providing confidence in subsequent safety assurance claims. Any deficiencies -such as hazards with no related operational tasks or operational tasks (deemed as safety-related by subject matter experts) with no relationship to identified hazards -can be highlighted. 

Task analysis and talk-through Performance objectives definition Performance situation specification Modelling of human performance Identification of potential human errors... 

The task analysis technique has been developed mainly to handle human factors (in HAZID and other methods). In HAZID this is helpful in addressing human factors such as human error, man—machine interface, and procedural error. Of the various hazard identification techniques, task analysis is one of the most important. The other techniques are discussed in subsequent chapters, but here discussions will be on task analysis. Task analysis is the study of what users need to do, in terms of actions and/or cognitive processes, to achieve a task objective. There are several factors, such as task duration, repetitive frequency, task allocation, complexity, equipment, ambience, and environmental conditions, which are required for the task and they very much influence the performance. At times, tasks are often used interchangeably with process. 

A review of accident, incident and ill-health records will also help with the identification. Other sources of information include safety inspection, survey and audit reports, job or task analysis reports, manufacturers handbooks or data sheets and approved codes of practice and other forms of guidance. 

Not all tasks require procedures also, different tasks require different kinds of procedures in terms of detail and format. The first key issue faced by procedure designers is the identification of those work tasks that require procedural aid. Organizations should have a formal process in place for identifying those safety-aitical tasks that require procedures. Approaches presented in the literature (e.g., Embrey, 1989 Marsden, 1996) advocate task analysis, such as hierarchical task analysis (HTA) (Stanton, 2006), followed by error analysis to identify the likelihood of operators failing a task and the level of criticality associated with failing to perform the task successfully. 

The step define task requirements comes after allocate function and define system performance (as shown in Figure 7.1). From a human factors point of view, a task analysis typically represents the first step to be undertaken, not one of the last. Just as functions can be subject to analysis, so can the tasks that move a system from function to function. A method that integrates functions and tasks in this way is called Task Analysis for Error Identification (TAFEI) (Baber and Stanton, 1994). Again, this is a reasonably comprehensive method for which only a brief summary can be provided. 

Task Analysis for Error Identification was developed to allow errors to be predicted, but in this context it can serve as a useful way of modeling the interaction between user and the system together, rather than separately. TAEEI assumes that people use systems in a purposeful manner, such that the interaction may be described as a cooperative endeavor. The technique makes the further assumption that actions are constrained by the state of the system at any particular point in the interaction and that the system offers information to the user about its functionality. 

Baber, C. and Stanton, N.A. (1994). Task analysis for error identification a methodology for designing error tolerant consumer products. Ergonomics, 37, 1923-1941. 

Techniques for the identification and evaluation of human error are typically labeled Human Reliability Assessments (HRA). A complete HRA starts with a definition of the problem and development of a task analysis to support the HRA (Kirwan, 2005). The core of HRA is the Human Error Identification (HEI) and Human Error Quantification (HEQ) stages, and several methods have been developed to specifically focus on these two areas. From these, control measures can be identified to reduce the overall system risk. 

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