Human Factors Best Practice

Minimum requirements drawn from legislation provide some highly useful generic insights. Human factors best practice supplements this with more focused methods that enable facets of the structure and process of communication to be diagnosed. 

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Shift Patterns (Chapter 9)—Shift patterns refer to the scheduling of work activity outside the standard office hours, such as in 24/7 control room operations. These operations assume continuous staffing aud a handover of duty from one team to another. The example shifts are assessed against human factors best practice. Comparison of the two proposed shift cycles (i.e., summer and winter) with a notional ideal on the HSE risk and fatigue indices reveals similar results. 

This radical example of joint optimization is presented to illustrate that, even in industries associated with high levels of automation, philosophies concerning how to deploy it can vary considerably. Human factors best practice is concerned with remedying the ironies and paradoxes of automation and in seeking joint optimization. The fundamental question is not one of what can be automated, rather what should be automated and specifically how. 

Where facilities exist in the automation to be able to undertake either type of automation, the guidance provided in BS/EN/ISO 11064-1 2001, combined with the human factors best practice to follow, will be helpful. 

BS/EN/ISO 11064-1 2001 has a considerable amount of human factors best practice already embedded within it. It is, of course, possible to benefit still further, particularly in terms of the methods (and sequence of methods) that can be used to undertake functional analyses, task analyses, actual allocation of function, and the diagnosis of cognitive and affective criteria. The standard touches on the concept of dynamic allocation of function and this is explored further in this section. 

An explicit allocation of function methodology designed by Marsden and Kirby (2005) provides a way to meet the twin goals of human factors best practice and BS/EN/ISO 11064-01 2001. Marsden and Kirby s method is comprised of three main stages ... 

In BS/EN/ISO 11064-1 2001 preliminary function allocations are performed using an overview approach comprised of four basic heuristics. Human factors best practice offers an extension to this approach in the form of Fitts List (Fitts, 1951). The expanded collection of heuristics is anchored around information-processing stages and the relative performance of humans or automation in performing them. Fitts List is shown in Table 7.4. 

The worked example that expresses some of the human factors best practice discussed above is based on an energy distribution system—specifically, the part of the total system that deals with the storage of gas. In this scenario, the task is concerned with alarms that warn control room operators of abnormal states. 

The first example reflects human factors best practice by illustrating the use of a freely available HTA tool. This tool enables many of the basic requirements of BS/ EN/ISO 11064-1 2001 to be met, including the definition of task requirements, using the outputs of the HTA, combined with heuristics, in order to perform a preliminary allocation of function, then going further to help meet the requirements for job design. 

From the above it is clear that shiftworkers often find themselves at potentially increased risk of health-related problems. It is also clear that these problems interact not only with each other but also within a wider context. Once again this highlights the need to adopt a systems perspective, as considering each aspect in isolation would not represent human factors best practice. 

The employee has a reciprocal duty of care under health and safety legislation, and it is incumbent upon them to take reasonable care of their own health and safety and that of other people who may be affected by their activities at work (HSE, 2006, p 2). To this end, employees need to take positive steps in order to cope with the challenges of shiftwork. It is only possible to deal briefly with human factors best practice in this area, but some key advice follows. 

In terms of human factors best practice it can be broadly recommended that shift handovers should not necessarily default to an overtly streamlined act. The risk is that efficiencies gained in the explicit situation come at the cost of the equally valuable implicit situation. In general, human factors best practice would suggest ample opportunity for interaction and team overlap, actively supported to create the conditions for favorable implicit interaction and situational awareness. 

Compliance with Human Factors Best Practice for Shiftwork... 

Human Factors in the Design and Evaluation of Control Room Operations 13.6.4.2 Human Factors Best Practice... 

The acoustical environment of the control room in our example was measured in accordance with the procedures just described and the results are shown in Table 13.17. is based on the dB(A) measure but is averaged over time so they are not directly comparable. What does draw note is the fact that the difference between minimum and maximum sound levels is comparatively wide. This quick assessment has served its purpose in identifying, at little cost (time or financial), that there was no need for further investigation. Note, however, that the character of the background or ambient sounds is acceptable in terms of human factors best practice. 

The guidance provided in the sections above represent a pragmatic way to ensure compliance with BS/EN/ISO 11064-6 2005. In general, the minimum standards posit easily measurable objective criteria for control room environments, and the human factors best practice goes further to offer not just quicker, more efficient ways of measuring compliance but also ways that map onto the subjectively felt experience of the control room environment itself. As the flowchart presented earlier suggests, having undertaken a first pass and perhaps manipulated some environmental variables, the opportunity should be taken to reevaluate the situation. This iterative cycle helps to ensure that the appropriate systems perspective is adopted (per BS/EN/ISO 11064-6 2005) and that optimum trade-offs are applied. 

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