Task analysis technique

Specific titles within each of the operating phases can be determined using a job task analysis in concert with the technology package and process safety information. Appendix D, ISD Model and Job Task Analysis Techniques, provides basic guidance in this useful method. 

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 term Task Analysis (TA) can be applied very broadly to encompass a wide variety of human factors techniques. Nearly all task analysis techniques provide, as a minimum, a description of the observable aspects of operator behavior at various levels of detail, together with some indications of the structure of the task. These will be referred to as action oriented approaches. Other techniques focus on the mental processes that imderlie observable behavior, for example, decision making and problem solving. These will be referred to as cognitive approaches. 

The task analysis techniques described in the previous section are mainly oriented toward observable actions, although hierarchical task analysis (HTA) allows it to address functional requirements as well as the specific actions that are required to satisfy these requirements. 

The question to answer for this pre-startup task is Who needs training for this process and to what level of detail One method to analyze training needs is offered by the Instructional Systems Design (ISD) technical training model. It points to the job task analysis method mentioned previously (Appendix D, ISD Model andJob Task Analysis Techniques) to identify procedure titles as a first step for determining which job positions require specific knowledge and skills. 

The human factors literature is rich in task analysis techniques for situations and jobs requiring rule-based behavior (e.g., Kirwan and Ainsworth 1992). Some of these techniques can also be used for the analysis of cognitive tasks where weU-practiced work methods must be adapted to task variations and new circumstances. This can be achieved provided that task analysis goes beyond the recommended work methods and explores task variations that can cause failures of human performance. Hierarchical task analysis (Shepherd 1989), for instance, can be used to describe how operators set goals and plan their activities in terms of work methods, antecedent conditions, and expected feedback. When the analysis is expanded to cover not only normal situations but also task variations or changes in circumstances, it would be possible to record possible ways in which humans may fail and how they could recover from errors. Table 2 shows an analysis of a process control task where operators start up an oil refinery furnace. This is a safety-critical task because many safety systems are on manual mode, radio communications between control room and on-site personnel are intensive, side effects are not visible (e.g., accumulation of fuel in the fire box), and errors can lead to furnace explosions. 

TABLE 3 Task-Analysis Techniques for Interactive System Design... 

Observation during task activity or shadowing workers throughout their daily work activities are time-consuming task-analysis techniques, but they can prove useful when it is difficult for informants to verbalize their task knowledge (Jeffries 1997). These techniques can also provide information about the environment in which tasks are performed, such as tacit behaviors, social interactions, and physical demands, which are difficult to capture with other techniques (Kirwan and Ainsworth 1992). 

Tailored from Human Factors Briefing Note Nr 12, The Institute of Petroleum, London, 2003. Kirwan and Ainsworth (1992) provide an exhaustive description of task analysis techniques. 

Embrey, D., 2000. Task Analysis Techniques. Human RehabUity Associates Ltd. downloaded from http //www.humanreliabihty.com/articles/Task%20Analysis%20Techniques.pdf on 1/12/15. 

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. 

D. Embrey, Task Analysis Techniques, MD Human Reliability Associates Limited. 

Embery, D. 2000. Task Analysis Technique, Human Reliability Associate. Available at www.humanreliahility. cotnlanicleslTask%20Analystf/o20Techniqiies.pdf. 

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