Task-based assessment

Afunctional task-based assessment is recommended to ensure that the measttred interface is effective and does not limit task performance or cause the user frustration when used. 

A new area of research concerns exposure assessment for beryllium in the production of nuclear weapons at nuclear defense industries. A safe level of exposure to beryllium is still unknown. Potential explanations include (1) the current exposure standard may not be protective enough to prevent sensitization, or (2) past exposure surveillance may have underestimated the actual exposure level because of a lack of understanding of the complexity of beryllium exposures. Task-based exposure assessment provides information not directly available through conventional sampling. It directly links exposure to specific activity associated with contaminant generation and provides in-depth evaluation of the worker s role in a specific task. In-depth task analysis is being used to examine physical, postural, and cognitive demands of various tasks. 

Seal, A. B. Bise, C. J. 2002. Case study using task-based, noise-exposure assessment methods to evaluate miner noise hazards. Mining Engineering, 54, 44-48. 

The Naval Medical Research Institute Performance Assessment Battery (NMRI-PAB) was developed to measure the effects of a wide variety of military environments upon the technically oriented tasks of Marine and Naval personnel. The battery s methodology was based on a tii-service methodology in an attempt to standardize measurement of human performance in military environments.41 The NMRI-PAB, like the WRPAB and UTC-PAB, is a menu-driven, microcomputer-based assessment tool that comprises individual tasks. 

Schema-based assessment puts the what and the why of assessment first, and it does so by supplying an integrated picture of memory, learning, and assessment. The schema comprises multiple knowledge components, each made up potentially of many different pieces of information. Any test item for a schema will call for some subset of one or more of these knowledge components. The task of the test developer is to create items to test various subsets and thereby estimate efficiently the completeness of an individual s schema knowledge.

Smith, R. W., Sahl, J. D., Kelsh, M. A., and Zalinski, J. (1997). Task-based exposure assessment Analytical strategies for summarizing data by occupational groups. Am Ind Hyg Assoc J 58, 402-412. 

The first task conducted in this project is to evaluate all of the competing technologies that could be utilized for each of the components in the entire fuel cell and vehicle fueling system based on the criteria of cost, performance, and technical feasibility. The goal of this initial, broad-based assessment is to select the most promising (four to five) system designs and technologies on the basis of the above criteria. 

In yet another alternative, it is frequently desirable to use values representing demands imposed by tasks (task A) ] as the reference for assessment of performance capacity measures. Demands on performance resources can be envisioned to vary over the time course of a task. In practice, an estimate of the worst-case value (i.e., highest demand) would be used in assessments that incorporate task demands as reference values. In one form, such assessments can produce binary results. For example, availability can be equal to or exceed demand (resource sufficiency), or it can be less than demand (resource insufficiency). These rule-based assessments are useful in identifying limiting factors, that is, those performance resources that inhibit a specified type of task from being performed successfully or that prevent achievement of a higher level of performance in a given type of task. 

Applying these three concepts makes it a much simpler yet effective task to assess the energy performance of a process unit and require minimal data. The EPI method is developed based on these concepts and designed for practical applications. 

Modeling health effects from various hazard levels is a difficult task. Risk assessments are typically based on the risk of death or serious injury. Obviously there are no experimental data available on the dose-response relationship of material concentration and exposure duration, thermal radiation intensity or blast overpressures on humans. What little there is has been inferred from actual accidents. Models that predict the impact of exposure to hazardous materials are heavily influenced by animal experiments. Typically, they have large safety factors built in. It is believed that models based primarily on exposure of experimental animals are conservative when applied to humans, especially when, on a body weight difference, the animals are much smaller than humans. In fact, many will argue that they are too conservative. These estimates are difficult to make, and unfortunately little can be done to improve the degree of uncertainty. 

A Task Based Risk Assessment wiU he performed after the detailed designs are completed.. .. A review of anticipated equipment and/or processes with the shop committee and the Local Joint Health and Safety Committee will he held. 

Task-based risk assessments be made in the design process when new programs are initiated. 

A multidiscipline validation team assures that the desired level of safety has been met when the equipment or process is installed, using safety checklists and the task-based risk assessment summary—aU to provide another look at the production system to verify that nothing has been missed. 

Crucial to the success of the UAW-GM joint process was the inclusion of the hourly skilled trades and production personnel, who were extensively involved in the task-based risk assessments. This involvement was based on the premise that the person who does a job every day has intimate knowledge of it and can make meaningful contributions on how a job or process can be changed to make it safer. (The TABRA process has matured now, internally developed computer-based software is used in the safety design review process and for recordkeeping.)... 

Table 1 provides task-based examples of exposure assessments. 

Better assessments identify named persons and target dates for implementing findings as part of the action plan. An example of a form to record a task-based risk assessment is provided at Appendix 5.1. 

The principles involved with fire risk assessment are very similar to those adopted for task-based and workplace-based risk assessment with a number of discrete differences, in particular many of the protective control measures are built in at the design stage of a building, as has already been discussed in Chapter 9. 

It is therefore essential when considering the fire risk assessment process to include not only the task-based or operations-based risks, which may cause a fire, but also the building risks that may prevent persons responding and being able to escape to a place of safety in the event of a fire. The principle of this chapter is to draw together all of the elements previously discussed within the preceding chapters to enable those completing a fire risk assessment to ensure that it is both suitable and sufficient. 

---