Human Error and Disturbance Occurrence in Manufacturing Systems (HEDOMS): A Framework and a Toolkit for Practical Analysis

New demands on modern manufacturing systems, such as increased flexibility, higher quality standards, customer responsiveness, and higher innovative capacities, have emphasised the need for higher levels of overall system reliability. Within this context disturbances play a critical role, because of the effects they may have on production or on safety, which are both strong determinants of overall system performance. The main focus of this paper is the reliability of manufacturing personnel and the way in which this interrelates with overall system performance. A framework – Human Error and Disturbance Occurrence in Manufacturing Systems (HEDOMS) – integrates human reliability with overall system performance, relating human error with disturbance occurrence and handling. HEDOMS has been extended into a toolkit to enable the identification of potential for human error and disturbance occurrence in manufacturing systems, as well as the definition of suitable error reduction measures.     

Multivariate Analysis of Human Error Incidents Occurring at Nuclear Power Plants: Several Occurrence Patterns of Observed Human Errors

This paper describes the results obtained in respect of typical human errors together with their information-processing phases, causal factors and situational factors found commonly among incidents analysed at domestic nuclear power plants (NPPs). The Central Research Institute of Electric Power Industry has been conducting detailed and structured analysis of all incidents reported during the last 31 years and has stored them in a database. At first, all case studies were classified into several categories. Next, multivariate analysis was applied. These results suggested that there were several occurrence patterns that were identified how errors occurred at NPPs in the past.     

Training Effective Human Performance in the Management of Stressful Emergencies

Emergency situations in industry occur suddenly and often unexpectedly; operators must make critical decisions under stress, and the consequences of errors can be immediate and catastrophic. Training effective performance under stress becomes an important aspect in the management of emergencies. This article proposes a taxonomy of cognitive strategies that enable operators to regulate their thinking and adapt decisions to changes in the demands of the situation. Cognitive strategies, such as, tolerating uncertainty, managing workload, planning for contingencies, and self-monitoring, provide the content of training emergency response. Stress, however, interferes with the learning of strategies, which presents a challenge to the design of training methods. Exposure to stress during training, degree of task decomposition, guidance, contextual variety and feedback are some of the training methods explored to facilitate the acquisition and transfer of cognitive strategies. Diversions from the traditional systems approach to training are pointed out and areas for further training research are identified.     

Human Factor Analysis of JCO Criticality Accident

The criticality accident that occurred on September 30, 1999 at a uranium processing plant in Tokai-mura was an unprecedented nuclear accident in Japan, not only because it caused deaths of two workers due to radiation casualty but also because it called for evacuation and sheltering indoors to nearby residents. The accident was not directly caused by failures or malfunctions of hardware but by workers’ unsafe action deviated from the approved procedure. It was a typical organizational accident in that several organizational factors worked behind. This article is to analyze various causal factors that lead to the accident, including situational factors of workers’ unsafe action that triggered the accident, operational and business management of the company, and nuclear safety regulation by the government. It also discusses problems of emergency response after the accident.     

MABA-MABA or Abracadabra? Progress on Human–Automation Co-ordination

In this paper we argue that substitution-based function allocation methods (such as MABA-MABA, or Men-Are-Better-At/Machines-Are-Better-At lists) cannot provide progress on human–automation co-ordination. Quantitative ‘who does what’ allocation does not work because the real effects of automation are qualitative: it transforms human practice and forces people to adapt their skills and routines. Rather than re-inventing or refining substitution-based methods, we propose that the more pressing question on human–automation co-ordination is ‘How do we make them get along together?’ Correspondence and offprint requests to: S. W. A. Dekker, Department of Mechanical Engineering, IKP, Link?ping Institute of Technology, SE - 581 83 Link?ping, Sweden. Tel.: +46 13 281646; fax +4613282579; email: sidde@ikp.liu.se     

Theory of Safety-Related Violations of System Barriers

This paper focuses on a theory of the safety-related violations that occur in practice during normal operational conditions, but that are not taken into account during risk analysis. The safety-related violations are so-called barrier crossings. A barrier crossing is associated to an operational risk which constitutes a combination of costs: the cost of crossing the barrier, the benefit (negative cost) immediately after crossing the barrier, and a possible deficit (extreme cost) due to the exposure to hazardous conditions that are created after the barrier has been crossed. A utility function is discussed which describes the consequence-driven behaviour and uses an assessment of these costs functions. An industrial case study illustrates the application of the proposed theory.     

Trust: Key Elements in Human Supervisory Control Domains

This study aimed to investigate the concept of trust within human supervisory control domains. Using repertory grid methodology, a small homogeneous sample of control engineers from two individual companies within the energy distribution industry were found to share a commonality in what they considered to be important characteristics of trust across three groups: intra-team, inter-team and technology. Sixty constructs were elicited which were reduced to 13 core constructs using content analysis. These were categorised into three separate dimensions; emotive, cognitive and behavioural. Differences were found, both within and between the three groups, according to participants’ scored level of trust for each group. These results are discussed with a view to developing strategies that may enhance trusting behaviours, especially between teams in applied controlled settings.     

Representations in Human–Computer Systems Development

When system developers design a computer system (or other information artefact), they must inevitably make judgements as to how to abstract the domain and how to represent this abstraction in their designs. Over the years human–computer interaction, or more generally information systems design, has had a history of developing competing methods and models for both the process and products of its development. Various paradigms have been suggested, often trying to keep pace with the changing nature of the design problem; from batch processing to interactive systems to work situations and most recently to designing for household environments. It appears timely, then, to review the nature of the design problem that faces the developers of human–computer systems and to consider some of the impact that different representations and different conceptualisations may have on their activities. Green (1998) has suggested that a single model of developing human–computer systems is not desirable, instead arguing for a number of limited theories each of which provides a useful perspective. The aim of this paper is to place competing methods side by side in order to see their strengths and weaknesses more clearly. The central tenet of the paper is that different views of both the human–computer system design process and the different abstractions, or models, that are produced during the design process have varying degrees of utility for designers. It is unlikely that any single method or modelling approach will be optimal in all circumstances. Designers need to be aware of the range of views that exist and of the impact that taking a particular approach may have on the design solution.     

Human Values and the Management of Technological Change

This paper looks at how human values influence the reception of technology in organisations. It suggests that we need to know what values are and how value systems evolve in order to manage technological change effectively. This proposition is based on research into the issues surrounding performance measurement as part of an information system, the cognition of which contains many parallels with that of technology. The analysis places human values’ theory within the context of systems thinking, where values are taken as system components, their groupings as systems and the expectations and behaviour produced by them as emergence.     

Human Factors in the Design of Supervisory Control Systems and Human–Machine Interfaces for Highly Automated Complex Systems

The design of control systems and human–machine interfaces in the field of complex and safety-critical environments remains today an open issue, in spite of the high technological evolution of the last decades. The increasing use of automation has improved efficiency, safety and ease of operations but, at the same time, it has complicated operators’ situation awareness and has changed the nature of their possible errors. The research activity described in this paper is an attempt to develop a methodological framework to support designers of control systems and human–machine interfaces. In particular, it focuses on the need for a deeply recursive approach related to the implementation of the systemic and human aspects of the design process of a human–machine system, intended as a Joint Cognitive System. A validating case study has been performed, based on the full application of the framework on the control of the turbine/alternator system of a thermoelectric power plant in northern Italy. Correspondence and offprint requests to: M. Piccini, Politecnico di Torino Dipartimento di Energetica, C.so Duca degli Abruzzi 24, 10129 Turin, Italy. Tel.: +39 011 564 4413; Fax: +39 011 564 4499; Email: mipiccin@polito.it     

Effects of Integrated Graphical Displays on Situation Awareness in Anaesthesiology

Anaesthetic information displays have been shown to influence anaesthesiologists’ situation awareness. In study 1 an object display was compared with the traditional display currently used. Twelve anaesthesiologists (residents and faculty members) participated in a simulator evaluation of the displays. Reaction times for detection of critical events and situation awareness were measured. The object display improved situation awareness for one of four test scenarios. Low-level situation awareness was higher with the traditional display, and medium-level situation awareness was higher with the new display. In study 2, an integrated 3D display was compared to the traditional display. Twelve students participated in the evaluation. The new 3D display helped the observers to see changes more rapidly. In one scenario, situation awareness was higher with the new display than with the traditional display. In summary, during 63% of the simulated scenarios, reliable differences were found in favour of the new displays. Thus, by introducing integrated graphical displays in the operating room, anaesthesiologists’ performance may be improved.     

Nuclear Reactor Control Room Simulators: Human Factors Research and Development

Simulator studies are powerful means for understanding, designing and managing the complexity of nuclear reactor control if, along with their scenarios, they are correctly designed for that purpose. This contribution to an international state of the art of the use of nuclear reactor control room simulators in human factors research and development summarises the trends and novelties in the theories and methodologies (the reduction of the ambitions of cognitive simulation and the renewal of process-tracing methods, the eclectic search for theoretical and methodological complementarity, the conquests of situation awareness and their limitations, the study of cooperation), in the use of the results (with stress on probabilistic human reliability analysis and design of procedures) and in the construction of simulated situations (with stress on part task simulations and on relations between testing practical and empirical hypotheses and testing theoretical ones).     

Quality-of-service adaptation in distributed multimedia applications

High-speed networks and powerful end-systems enable new types of applications, such as video-on-demand and teleconferencing. Such applications are very demanding on quality of service (QoS) because of the isochronous nature of the media they are using. To support these applications, QoS guarantees are required. However, even with service guarantees, violations may occur because of resources shortage, e.g., network congestion. In this paper we propose new adaptation approaches, which allow the system to recover automatically, if possible, from QoS violations (1) by identifying a new configuration of system components that might support the initially agreed QoS and by performing a user-transparent transition from the original configuration to the new one, (2) by redistributing the levels of QoS that should be supported, in the future, by the components, or (3) by redistributing the levels of QoS that should be supported immediately to meet end-to-end requirements based on the principle that (local) QoS violation at one component may be recovered immediately by the other components participating in the support of the requested service. The proposed approaches, together with suitable negotiation mechanisms, allow us (1) to reduce the probability of QoS violations which may be noticed by the user, and thus, to increase the user confidence in the service provider, and (2) to improve the utilization of the system resources, and thus to increase the system availability.     

Broadband Cellular Radio Telecommunication Technologies in Distance Learning: A Human Factors Field Study

This paper presents a virtual classroom field experiment utilising broadband cellular radio telecommunication technologies and involving real users. The aim of the investigation was to experiment in the field cellular broadband systems in realising virtual classroom situations. In particular, we investigated learners’ performance and usability aspects of the multimedia tele-education system including ease of use, usefulness, telepresence and users’ satisfaction about the system. Results confirmed the effectiveness of the multimedia system in terms of both technical and psychological features. Some operational results and practical solutions were obtained as well. They included the basic features of multimedia systems used in virtual classroom and the correct procedures for training teachers and learners in the equipment use.     

Understanding Perceived Complexity in Human Supervisory Control

Industrial processes are becoming more complex owing to technological developments and new opportunities. Technological developments, hardware and software, have become more reliable and system configurations more robust. However, the reliability of operator control actions has not improved at the same pace. Consequently human reliability has become the relatively weakest aspect of automated, operator-supervised systems. Hence, understanding how the human operator experiences increasing complexity may play an important role in task allocation and human–machine system design. In this paper the perceived complexity is studied within four typical operational environments in supervisory control. Mathematical formulations for these four operational environments are proposed, and their properties are analysed. A laboratory system is used to investigate the perceived complexity under various operational environments. The experimental results show a significantly different perceived complexity for the coupled and uncoupled operation environments. Extrapolation of the results revealed that the operator would have perceived the system as extremely complex if he/she would have to operate more than eight strongly interconnected subsystems extensively in 30 minutes. Implications of this study are also addressed.     

Analysis and Classification of Human Driving Behaviour in an Urban Environment*

Intelligent vehicle systems have introduced the need for designers to consider user preferences so as to make several kinds of driving features as driver friendly as possible. This requirement raises the problem of how to suitably analyse human performance so they can be implemented in automatic driving tasks. The framework of the present work is an adaptive cruise control with stop and go features for use in an urban setting. In such a context, one of the main requirements is to be able to tune the control strategy to the driver’s style. In order to do this, a number of different drivers were studied through the statistical analysis of their behaviour while driving. The aim of this analysis is to decide whether it is possible to determine a driver’s behaviour, what signals are suitable for this task and which parameters can be used to describe a driver’s style. An assignment procedure is then introduced in order to classify a driver’s behaviour within the stop and go task being considered. Finally, the findings were analysed subjectively and compared with a statistically objective one.     

How to Manage Human Error in Aviation Maintenance? The Example of a JAR 66-HF Education and Training Programme

While maintenance is not a frequent cause of accidents in aviation, maintenance-related accidents tend to be very serious. Thus there is a great potential for improving safety in the maintenance area. In the aviation maintenance domain, the Joint Aviation Authorities have specified a training programme aimed at maintenance technicians called JAR 66 (JAR = Joint Aviation Requirements). This regulatory text encompasses 17 chapters. While most of these chapters address technical matters, Chapter 9 concerns Human Factors. The chapter is itself divided into nine modules ranging from physiology to cognitive and social psychology, and to hazards management. In 1999, in order to comply with this new regulation, De′dale and Air France have jointly developed a three-day training programme on Human Factors for certifying staff maintenance. The course has since become the first JAR 66 certified HF course in France. This paper has two complementary objectives: the first one is to present the method by which the courseware was developed to fulfil the JAR requirements, and the second one is to discuss ‘Error Management’, a central issue of the course, and how error management may be tackled by training and practical approaches (e.g., incident reporting) within a organisation.     

The New Frontier Issues for Cognition Technology

Cognitive engineering has developed enormously over the last fifteen years. Yet, despite many excellent research projects and publications, its full potential has not been embraced into mainstream system design. This paper will examine the reasons for this failure and argue that the problem is not simply inertia or lack of education. There are strong organisational influences that cause resistance to this particular approach. The discipline itself has characteristics that make it fragile in the modern corporate structure. In addition, the cognitive engineers themselves are not blameless in the equation. They appear to have done exactly what they criticise the engineering community for doing: they have packaged their product in a manner that is not ‘user friendly’ to its target population, not structured to suit its application, and not output in the format required. Suggestions will be made to rectify the situation: a list of actions is proposed for practising cognitive engineers to make their product more likely to enjoy widespread uptake.     

Cognitive Theories and Engineering Approaches for Safety Assessment and Design of automated systems: A Case Study of a Power Plant

This paper concerns methods and techniques for analysis and assessment of human factors in automated plant. A well-known theory is reviewed and an engineering approach is devised for retrospective accident evaluations and prospective studies. The lessons learnt from a serious accident for the safety assessment of a real plant are discussed in detail. The relevance of the human contribution to the accident and the likely improvements identified by the application of the method confirm the importance and advantages of performing accurate human factors analyses for design and safety of technological systems.