Human factors specialists

Operations and human factors specialist involvement is important to find optimum solutions to human factors/ergonomics issues. Applying inherent safety principles to ergonomics/human factors issues can reduce risks associated with ... 

Human errors may be dependent on the specific accident sequence displayed in the event tree, and, for that reason, may be included in the event tree. This requires the human-factors specialist to consider the context of the error in terms of stress, operator training in response to the accident, di.tgnosiic paiierns, environmental, and other performance-shaping factors. 

It should be emphasized that the PIFs considered in this chapter, although generally considered important by human reliability specialists, are not meant to be exhaustive in their coverage. Other selections, such as those considered by the methods such as TRIPOD and HP AM (Chapter 2), are possible. It is recommended that the advice of an experienced human reliability or human factors specialist is sought when deciding which PIFs should be covered in a specific situation. 

The term control panel refers to the instrumentation console in a central control room through which process information is communicated to the process worker and via which the worker changes the state of the process. This category includes display elements such as chart recorders, bar indicators, dials, and modem VDU-based systems together with control elements such as buttons, switches, track balls and mice. The control panel is the human-machine interface (see Chapter 2) that has traditionally received the most attention from human factors specialists. 

Table 3.4 presents a list of human factors that may positively or negatively influence the likelihood of operator error. This list may be used prior to, and/or during the analysis. In addition, the PrHA team may determine that human factors problems are of sufficient importance or complexity to require the assistance of a human factors specialist. 

Process control (electrical/instrumentation) engineer Industrial hygienist Maintenance engineer Materials engineer/metallurgist Human factors specialist... 

Several detailed performance measures were collected, comprising extensive information about the various phases of the scenario corresponding to the defined HFEs. However, for the present paper, audio/video recordings coupled with simulator log data, constituted the fundamental sources for writing partial communication extracts and narratives of crew performance of the HFEs, and for allowing detailed understanding of what the crews did, when they did it, and why. Interdisciplinary teams of operational experts and human factor specialists performed all analyses these constitute the source material for the analysis presented in this paper. Quantitative and qualitative results about the crew performance of the HFEs, the drivers of performance and the observed difficulties will be reported in a Halden Work Report (HWR) and later in a NUREG report, as part of the International Empirical HRA study. 

During the concept phase, the human factors specialist performs tasks such as the following [3,24] ... 

Designers are concerned witli the interaction between humans and machines. This area has become increasingly sophisticated and specialized. Books on Human Factors have been written for the design engineer rather than the human factor specialist. The books provide the engineer with guidelines for designing products for convenient use by people. 

An interactive GPCA-Ul prototype is now presented that incorporates the verified PVS specification. The utility of the prototype is that it allows validating the behaviour of the generated code, and verifying aspects of the UI that are not formalised in the specification (e.g., the guidelines illustrated in Section 3.1). Additionally, the prototype can be used by formal methods experts to engage with domain experts such as human factors specialists. 

The most important contribution from the eigononrics/human factors specialists is the provision of more and wider information which is specifically tailored to mining and which is presented in a designer-friendly format. Both the design aids for designers and MISHC/EMESRT approaches follow this principle but their application is still relatively limited in relation to the size of the designed-in accident problem in nuning equipment. 

In addition, there is an increasing need for more research on the ergonomics/ human factors of remote control and automation/semi-automation in the mining context. Research in other industrial sectors, such as defence or rail transport, has found that there is the potential for automated systems to overload, confuse and distract, rather than assist, an operator imless it is ergonomically designed. Therefore the human factors specialist can assist with issues such as ... 

Although not primarily written for human factors specialists, there is within the text a considerable body of real examples of human error which has, or is likely to, predispose accidents and a number of techniques and approaches which are probably not widely known outside of the mining human factors fraternity. It... 

Two major approaches can be quoted to characterize human error the probabilistic and the causal one (Rouse Rouse 1983). Typically, the probabilistic approach is pursued by reliability engineers and human factors specialists trying to measure human reliability in terms of the same features as those of equipment to give an estimate of reliability of the system as a whole (Adams 1982). Human failure rates regarding particular types of tasks and procedures serve as an input for human risk assessment. In contrast, the causal approach to characterizing human error is based on the premise that errors are rarely random and, in fact, can be traced back to causes and contributing factors in order to propose improvements. 

In a first attempt, Swain Guttmann (1983) provided five levels of dependence, ranging from zero to complete dependence, and the corresponding conditional probabilities for tasks in nuclear power plants. Thus, the human factors specialist has to decide for each task what kind of dependency exists in order to apply the correct formulas to work out failure probability. 

Major sources of uncertainty in human reliability analysis include the availability of actuarial data on human error probabilities and the variability of human performance. Human factors specialists call for the institution of data banks concerning human error that would be used in the same way as equipment data banks. For HEP one would like to know the number of errors for each action that occurred and how many times these actions were performed. For the present, the state of behavioral data remains insufficient. Most of the estimates of hep s represent extrapolations from human error data based on tasks performed in a variety of settings, e.g. within process industries and in industrial and military settings. Due to variations in equipment, tasks, and environment, errors are hardly comparable. 

---