Analysis Tasks

The aim of this chapter is to deal with the first task, analysis of the quality of data. Very quickly we are going to demonstrate how to get high quality data, before we move on to show how they become useful for learning. 

Are job criteria formalized in job descriptions for each position Is there a more detailed job task analysis or profile ... 

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. 

An example of procedures found by performing a job task analysis would be rework procedures. Occasionally, out of specification product is produced which can be reworked in the process. This subcategoiy of normal operations phase procedures may require special consideration. While rework can be a straightforward operation, it could have safety consequences if done improperly. 

The analysis phase of the instructional systems design (ISD) model, as referred to in Chapter 4, consists of a job task analysis based upon the equipment, operations, tools, and materials to be used as well as the knowledge and skills required for each position. Most important in this phase is the selection of the performance and learning objectives each employee must master to be successful in their job as related to the toll. 

Job analysis produces a task list. This list helps identify procedure titles. Task analysis identifies training topics and skills. 

Task analysis A method for determining the detailed performance required of people and equipment and determining the effects of the surroundings, malfunctions, and other unexpected events on both. 

Consider a task analysis for Do-ability. Can the operators do what we have asked them to do Tasks and facilities should be designed with knowledge of ergonomic considerations and performance shaping factors (PSF) so that operator reliability can be designed into the task. 

TALENT Task Analysis Linked EvaluatioN Technique NUREG/CR-5534, 1991... 

At this point, a task analysis is performed. A "task" is defined as an activity oi performance (hat the operator sees as a unit either because of its performance character]stic.s or becau.se that activity is required as whole to achieve some part of the system goal. Only the tasks that are relevant lo the system safety are considered. A task analysis involves decomposition of each task into individual units of behavior. Unusually, this analy.sis tabulates information about each specific human aciiun. The format of such a table is not rigid - any style that allows easy retrieval ot the information can be used. The format reflects the level of detail and the type of task analysis performed. The analysis yields... 

Errors of omission and com mission are identified for every human action appearing in the task-analysis table. A human action (or lack thereof) constitutes an error only if it has at least the potential for reducing the probability of some desired event or condition. The existence of this potential should be identified with the system analysts. 

For every human action appearing in the task-analysis table, errors of omission and commission should be pinpointed. 

The HRA evaluates errors that may affect the probabilities of system success and failure but do not appear in ihc task analysis. Some of these can he disregarded by assuming that a certain condition does or does not exist. For example, for a post-inamienance losi. the concern is for... 

A probabilistic statement of the likelihood of human-error events presents each error in the task analysis as the right limb in a binary branch of the HRA event tree. These binary branches form the chronological limbs of the HRA event tree, with the first potential error siai ting from the highest point on the tree. (Figure 4.5-4). Any given [ask appears as a two-limb branch the left limb represents the probability of success the right limb represents the probability of failure. 

The development of the HRA event tree is one of the most critical parts of the quantification of human error probabilities. If the task analysis lists the possible human error events in the order of ihcir potential occurrence, the transfer of this information to the HRA event tree is fadlitutcd. Each potential eiTor and success is represented as a binary branch on the HRA event tiec. with subsequent errors and successes following directly from the immediately preceding ones. Cure should be taken not to omit the errors that are not included in the task analysis table but might affect the probabilities listed in the table. For example, administrative control errors that affect a task being performed may not appear in the task analysis table but must be included in the HRA event tree. 

However, given appropriate traming, it is quite feasible for personnel such as engineers and process workers to apply techniques such as task analysis (Chapter 4) and audit methods (Chapter 3) to reducing error potential in the workplace. 

The first component of the systems approach to error reduction is the optimization of human performance by designing the system to support human strengths and minimize the effects of human limitations. The hiunan factors engineering and ergonomics (HFE/E) approach described in Section 2.7 of Chapter 2 indicates some of the techniques available. Design data from the human factors literature for areas such as equipment, procedures, and the human-machine interface are available to support the designer in the optimization process. In addition the analytical techniques described in Chapter 4 (e.g., task analysis) can be used in the development of the design. 

Human Factors Engineering/Ergonomics approach (control of error by design, audit, and feedback of operational experience) Occupational/process safety Manual/control operations Routine operation Task analysis Job design Workplace design Interface design Physical environment evaluation Workload analysis Infrequent... 

Perform task analysis (see Chapter 4) and identify skill, rule or knowledge-based tasks or aspects of tasks (the flow diagram in Figure 2.7 may be used to assist in this classification). 

Perform task analysis and classify skill, rule or knowledge-based behaviors involved in the scenario being evaluated. 

Taking the observed error or near miss as a starting point, perform task analysis (see Chapter 4) to describe overall context of the error. 

BEST 9 Detailed procedures and checklists available Procedures developed using task analysis Integrated with training Noise levels at ideal levels Lighting design based on analysis of task requirements Temperature and humidity at ideal levels... 

The first questions to be considered when designing a control panel are what information is required and how much of it will be appropriate. Too little information may increase the amount of inference that the worker is required to make to predict the state of process parameters that are not directly displayed. This is especially important for emergency situations where the human information processing system is taxed heavily with many tasks. On the other hand, too much redimdant information can overload the worker. It is essential, therefore, that the information needs of the worker are identified through some form of task analysis and worker interviews. 

In general, little use is made in the process industry of more sophisticated approaches such as job and task analysis (see Chapter 4) to define the mental and physical skills required for specific types of work, and to tailor the training program accordingly. Instead, informal on-the-job training is common, even in more complex types of work such as control room tasks. Although the necessary skills will eventually be acquired by this process, its inefficiency... 

Job and task analysis. This involves applying techniques such as hierarchical task analysis (see Chapter 4) to provide a comprehensive description of the work for which training is required. The task analysis provides essential information on the content of training. 

The third category of methods addressed in this chapter are error analysis and reduction methodologies. Error analysis techniques can either be applied in a proactive or retrospective mode. In the proactive mode they are used to predict possible errors when tasks are being analyzed during chemical process quantitative risk assessment and design evaluations. When applied retrospectively, they are used to identify the underlying causes of errors giving rise to accidents. Very often the distinction between task analysis and error analysis is blurred, since the process of error analysis always has to proceed from a comprehensive description of a task, usually derived from a task analysis. 

The following techniques can be used to collect data about human performance in CPI tasks and provide input to task analysis methods described in Section 4.3. These data can include process information critical for the task, control strategies used by the workers, diagnostic plans etc. A distinction can be made among data collection methods that provide qualitative data (such as interviews, observations, and sources of documentation) and methods that can be used to measure aspects of performance (such as activity analysis, simulations, and information withholding). The latter methods can provide more precise data which can be quantified. 

To provide data for task analysis methods concerning the difficulties involved in the performance of a task... 

Reference to such documents may be useful at early stages in the task analysis to inform the analyst about the overall nature and breadth of tasks carried out. Later, as the detail of the task is becoming established, such documents serve to provide crucial information. The use of experts in helping with the interpretation of documents is usually necessary, vmless the analyst is directly involved with the system on a regular basis. 

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. 

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