Audits, human factors

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... 

Although the main thrust of the HSE work is directed to providing inputs to the CPQRA process, the audit procedure generates valuable qualitative information regarding both the quality of the overall plant management and also the specific human factors dimensions which affect risk. 

In subsequent sections the application of PIFs to various aspects of error reduction will be described. One of the most important of these applications is the use of comprehensive lists of PIFs as a means of auditing an existing plant to identify problem areas that will give rise to increased error potential. This is one aspect of the proactive approach to error reduction that forms a major theme of this book. This application of PIFs can be used by process workers as part of a participative error reduction program. This is an important feature of the human factors assessment methodology (HFAM) approach discussed in Section 2.7. 

In the case of root cause analysis systems, more comprehensive evaluations of PIFs will normally be carried out as part of a full-scale human factors audit. This could make use of the types of comprehensive PIF evaluation methods described in Chapter 2 (see Section 2.7.7 and Figure 2.12). 

The case study described here concerns a human factors audit of a computer controlled process system which was being introduced in a distillation imit of a chemical plant. The unit was in transition from replacing its pneumatic panel instrumentation with the new system. However, control had not yet been transferred and the staff were still using the panel instrumentation. The role of the project was to evaluate a preliminary design of the computer-based display system and provide recommendations for future development. 

The human factors audit was part of a hazard analysis which was used to recommend the degree of automation required in blowdown situations. The results of the human factors audit were mainly in terms of major errors which could affect blowdown success likelihood, and causal factors such as procedures, training, control room design, team communications, and aspects of hardware equipment. The major emphasis of the study was on improving the human interaction with the blowdown system, whether manual or automatic. Two specific platform scenarios were investigated. One was a significant gas release in the molecular sieve module (MSM) on a relatively new platform, and the other a release in the separator module (SM) on an older generation platform. 

TABLE 7.1 Data Collection Techniques in the Human Factors Audit ... 

The Data-CoUection Instrument 1136 HUMAN FACTORS AUDITS 1151... 

When we audit an entity, we perform an examination of it. Dictionaries typically emphasize official examinations of (financial) accounts, reflecting the accounting origin of the term. Accounting texts go further for example, testing and checking the records of an enterprise to be certain that acceptable policies and practices have been consistently followed (Carson and Carlson 1977, p. 2). In the human factors field, the term is broadened to include nonfinancial entities, but it remains faithful to the concepts of checking, acceptable policies/practices, and consistency. 

Human factors audits can be applied, as can human factors itself, to both products and processes. Both applications have much in common, as any process can be considered as a product of a design procedure, but this chapter emphasizes process audits because product evaluation is covered in detail in Chapter 49. Product usability audits have their own history (e.g., Malde 1992), which is best accessed through the product design and evaluation literature (e.g., McQelland 1990). 

A second point needs to be made about the scope of this chapter the role of checklists. As will be seen, checldists have assumed importance as techniques for conducting human factors audits. They can also be used alone as evaluation devices, in applications as diverse as VDT workplaces (Ctikir et al. 1980), and risk factor assessment (Keyserfing et al. 1992). Hence, the structure tuid use of checklists will be covered in some detail independently of their use as an auditing technique. 

Such changes in the structure of the ergonomics/human factors profession indeed demand different evaluation methodologies. A powerful network of individuals, for example, who can, and do, call for human factors input in a timely manner can help an enterprise more than a number of individually successful project outcomes. Audit programs are one of the ways in which such evaluations can be made, allowing a company to focus its human factors resources most effectively. They can also be used in a prospective, rather than retrospective, manner to help quantify the needs of the company for ergonomics/human factors. Finally, they can be used to determine which divisions, plants, departments, or even product fines are in most need of ergonomics input. 

Such a procedure can also form a logical basis for human factors audits. The first step chooses the areas of study, the second samples the system, the third analyzes these samples, and the final step produces an audit report. These define the broad issues in human factors audit design ... 

If standards and other good practices are used in a human factors audit, they provide a quantitative basis for decision making. Measurement reliability can be high and validity self-evident for legal standards. However, it is good practice in auditing to record only the measurement used, not its relationship to the standard, which can be estabUshed later. This removes any tempteition by the analyst to bend the measurement to reach a predetermined conclusion. Illumination measurements, for example, can vary considerably over a workspace, so that an audit question ... 

Usability refers to the auditor s ease of use of the audit system. Good human factors principles should be followed, such as document design guideUnes in constructing checklists (Patel et al 1993 Wright and Barnard 1975). If the instrument does not have good usabiUty, it will be used less often and may even show reduced reliability due to auditors errors. 

In any sampling, we must define the unit of sampling, the sampling frame, and the sample choice technique. For a human factors audit the unit of sampling is not as self-evident as it appears. From a job-evaluation viewpoint (e.g., McCormick 1979), the natural unit is the job that is composed of a number of tasks. From a medical viewpoint the unit would be the individual. Human factors studies focus on the task/operator/machine/environment (TOME) system (Drury 1992) or equivalently the software/hardware/environment/Uveware (SHEL) system (ICAO 1989). Thus, from a strictly human factors viewpoint, the specific combination of TOME can become the sampling unit for an audit program. 

The ERNAP audits have been included here to provide examples of a checklist embedded in an audit system where the workplace is not the sampling unit. They show that non-repetitive tasks can be audited in a valid and reliable manner. In addition, they demonstrate how domain-specific audits can be designed to take advantage of human factors analyses already made in the domain. 

Besides outcome measures, interviews represent a possible data-collection method. Whether directed or not (e.g., Sinclair 1990) they can produce critical incidents, human factors examples, or networks of communication (e.g., Drury 1990a), which have vrilue as part of an audit procedure. Interviews are routinely used as part of design audit procedures in large-scale operations such as nuclear power plants (Kirwan 1989) or naval systems (Mrilone et al. 1988). 

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