Applied Ergonomics 1981, 12.2, 111-115

The design of an accident investigation procedure Mary Edwards

Department of Engineering Production, University of Birmingham

In August 1980, a joint meeting of the lEA and the NES was held in Oslo to discuss "Ergonomics in Action - From Theory to Practice" and papers were invited to illustrate this theme. It is the burden of this paper that ergonomics is not widely practised partly because the model of application implied in the conference theme is inappropriate and partly because ergonomists tend to be laboratory- rather than problem-centred. Some of the constraints associated with problem-centred research in organisations are discussed and a particular problem of applied ergonomics, as it relates to the design of accident investigation procedures, is described.

Ergonomists frequently complain, with justification, that ergonomics is overlooked by industry and commerce, that designers do not take proper account of the human operator, that man is the last system element to be considered. Why has ergonomics failed to make an impact after 30 years? Why is the transition from Theory to Practice proving so difficult?

Theory and practice Perhaps one of the reasons is that model of application

implicit in the conference theme is inappropriate. This one-step linear model of application suggests that developments in 'theory' take place in the laboratory and are then applied, often by different people ('practitioners', designers) to problems in the real world. This model of application derives from the natural sciences in which, to quote the Tavistock Institute (1964), "fundamental data are reached by abstracting the phenomena to be studied from their natural contexts and submitting them to basic research through manipulation in the laboratory. It is only later that possible applications may be thought of and it is only then that a second process is set under way". The attractions of the laboratory are evident; the problem is reduced to its essentials, contamination from extrinsic variables may be eliminated, a controlled investigation in which all the variables are systematically manipulated becomes feasible. Unfortunately, the removal of a problem from its context can rarely be accomplished without the loss of concomitant factors whose importance is unknown and whose neglect is likely to invalidate the solution for real world application.

Unlike those of the natural sciences, the fundamental data of ergonomics cannot be obtained by abstraction from natural contexts; they must be sought in their natural contexts. Chapanis (1976) has summarised some of the inadequacies of laboratory studies in terms of their relevance to real world application. He points out that "at best, laboratory experiments are rough and approximate models of real life situations. A laboratory experiment can

select only a few independent variables for test: unsuspected interactions in real life may nullify or even reverse conclusions reached in the l abora to ry . . , the effects discovered may be so small that they are of no practical consequence. The dependent variables used in the laboratory are usually variables of convenience, rarely selected for their relevance to any practical situation. Further, the methods used to present variables in the laboratory are often artificial and unrealistic".

The enthusiasm for the laboratory may be explicable, in part, in terms of the academic milieux in which ergonomists are primarily to be found and in which they experience pressures to conform to the values of an academic community. These values emphasise the importance of controlled experiments, of clear-cut significant results and, above all, of publication. Research rooted in the real world does not readily lend support to these values. Controlled experiments are often impossible, results are rarely clear-cut and at least two obstacles are likely to hinder publication, viz, problems of confidentiality and the difficulty of satisfying the academic standards of editors of learned journals.

It is instructive to consider the model in relation to the historical genesis of ergonomics. The distinction between theory and practice originally was not within ergonomics itself but between ergonomics and its parent disciplines. Ergonomics was conceptualised as a technology. It was problem-centred, concerned with applications, drawing on the subject matter of psychology, physiology or any other discipline which appeared relevant to the solution of the problem. The division between theory and practice has been displaced since that time and now appears to fall within the province of ergonomics. Is this displacement more apparent than real? Would it not be more helpful to label those areas of ergonomics not directly concerned with application as physiology, psychology, anatomy and reserve the word 'ergonomics' strictly for work arising from a problem in the real world for which a solution in the real world is implemented?

0003-6870/81/02 0111-05 $02.00 © IPC Business Press Applied Ergonomics June 1981 111

The real world problem to be discussed here may be considered at two levels. At one level, the problem concerned the inadequacies in the accident information and reduction systems in operation in industry. At the second level, there were problems of investigating the current system and attempting to implement a solution. This second level may be described as a 'meta-problem'.

The meta-problem This 'meta-problem' includes all those problems associated

with gaining access to an organisation and obtaining facilities for investigating the problem and implementing a solution. It operates as a constraint on the activities of the ergonomist, whether or not he is aware of it. The particular problems of a consultant or an internal practitioner will differ in detail from those of a research worker, though a certain commonality will be evident.

Gaining access to the organisation in order to carry out research is a problem applying particularly to an independent research worker seeking a research site. The selection of an organisation to which an approach can be made is not random. It is guided by the previous experience of the research worker or his colleagues that some organisations are more ready than others to agree to provide facilities. Thus the organisations in which research is carried out are not necessarily typical. Their acceptance of research workers may be indicative of additional characteristics which distinguish them from other organisations.

The attainment of access in the past, however, is not a guarantee that access may be obtained on all future occasions. The sponsorship of the research, the state of industrial relations in the organisation and the expectations of the organisation of how research is conducted are important factors in the decision. In the present case, it was made explicit to the researcher that sponsorship by the Health and Safety Executive (a body constituted by Act of Parliament to oversee health and safety in industry) prejudiced the organisation in favour of agreeing to provide research facilities. Expectations of what a research worker will do may influence not only agreement to provide access, but also agreement to implementation.

In one of the companies approached research was equated with 'doing a survey' which was congruent with the request to study the system. Within three weeks of the initial approach, it was possible to start the investigation. In the second company, research was equated with 'doing experiments' and three months elapsed between the initial approach and the start of the investigation, during which period requests from the organisation for specific proposals to consider were countered with requests for facilities initially to become familiar with the system. The extent to which 'industrial relations' are a problem in an organisation, or parts of it, will influence the extent to which access is granted. In one company the agreed research site was carefully selected as one without problems of this kind and where, accordingly, the introduction of an observer would not upset the equilibrium. In the other company requests to interview safety representatives were refused, as this was considered a delicate area.

Thus access is not granted unconditionally. Investigation may be restricted to particular areas of the organisation which may not be representative and limitations, both

implicit and explicit, placed on the activity of the research worker.

Approaches to organisations for research fhcilities are made to individuals. The role and function of the approached individual will influence the likelihood of gaining access and the limitations on access once it is achieved. The research worker is likely to be perceived as an adjunct to his organisational sponsor, with attendant advantages and disadvantages.

A distinction should be drawn between 'doing experiments' in an organisation and implementing a solution to a problem. In the former case, the organisation provides a setting and other facilities but essentially these activities are insulated from the rest of the organisation and have no serious implications for it. Implementing a solution, on the other hand, demands commitment from the organisation, a readiness to accept change and the adjustment of the organisation to a new 'modus operandi'. The implications are significant. These differences are reflected in the lengthy negotiating period in which solutions are discussed, rejected, modified, revised until they are considered acceptable to the organisation.

Implementation also demands from the research worker or consultant an ability to tolerate the gradual erosion of 'ownership' of the solution, to accept the compromises without which implementation is not considered feasible but which may modify the original intentions of the design, and to recognise that successful implementation must be a joint enterprise between the ergonomist and others in the organisation.

The problem The problem to which the research was addressed has

been recognised in general terms. A report by the Health and Safety Executiveqn 1976 commented on the 'haphazard' nature of accident investigation and analysis in industry and stated that "none of the factories (studied) had an information system which could be used as a base for constructive and positive accident prevention policy" although "much time and effort is given to collecting information which is then not put to any constructive use".

Adams (1974) has observed that the information about injury collected in industry "tell us nothing about how rates of injury or the absolute numbers of injuries may be reduced". Hartwell and Adams (1977) concluded that "accident reporting systems have not been designed as information systems but have grown in a relatively unplanned way". Hartwell (1977) noted that "much effort is expended in seeking or avoiding blame and responsibility for accidents". Powell et al (1971) found that only 5% of those accidents observed in one workshop were reported, and concluded that there was an incentive not to report any but the most serious accidents and that the factors contributing to this were primarily loss of time, suspicion, acceptance of minor injuries and the reporting system itself.

To rectify this situation, the Accident Advisory and Prevention Unit has called for a method of reporting accidents capable of providing "an accurate and effective basis for line haanagement decision making" (ibid.). This emphasises that the critical element in an accident information system is the feedback loop whereby information from accidents that have occurred is used by

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management for decision making aimed at modifying the situation to prevent or reduce subsequent accident incidence.

The investigation The first step in attempting to devise a solution was to

investigate the accident information systems in operation in industry in order to describe in more detail the nature of the problems and to understand the factors to be taken into account when designing and implementing a solution.

Two major companies were approached and their cooperation requested in providing facilities for the research worker to carry out an investigation of their accident information systems with a view to developing procedures aimed at enhancing accident reduction, if these appeared after the investigation to be necessary. The response to these requests was positive and studies were made in each company of the flow of accident information and the actions associated with this information.

Summary of findings Legal constraints

In spite of differences in detail, there were similarities in the two companies with regard to some major factors affecting the reporting and investigation of accidents. To some extent, these stemmed from the legal constraints surrounding health and safety in industry. Common to all British industry are the statutory requirements relating to accident reporting and the legal responsibilities enshrined in the Health and Safety at Work Act (1974). These include the notification to the Health and Safety Executive of accidents resulting in the loss of three days' work for the injured person and the appointment by recognised Trade Unions of Safety Representatives (usually shop stewards) whose function it is to facilitate cooperation between employers and employees in matters relating to health and safety.

In general, the investigation of accidents involving lost time was carried out by the Safety Officer, often in the company of a Safety Representative who is legally entitled to investigate these accidents. The initial report of a lost time accident was made by the Supervisor, in narrative form, and this report formed the basis of the formal report to the Health and Safety Executive. The investigation (if any) of minor accidents was the responsibility of the Supervisor. In both companies, Safety Committees discussed lost time accidents and minor injuries at their monthly meetings.

Model of accident causation The model of accident causation implicit in accident

reports, in discussion of accident incidence and in policies for accident reduction was characterised by an emphasis on culpable error, in the primacy of proximate factors in accident incidence and by a concept of safety as an optional, albeit desirable, extra.

The consequence of regarding culpable error as a major cause of accidents was to regard the only practical policy for accident reduction as the encouragement of 'self discipline'.

Accidents resulting in injury necessarily involve a victim. An activity of the victim usually precipitates the injury and thus the victim can in some sense be seen to have

contributed to his own distress. This is perhaps most clearly evident when the 'cause' of the accident is categorised as violation of procedures

There is a reluctance or inability on the part of the management to enforce rules and consequently norms develop which are based on behaviour which is in violation of the rules. These norms often have the effect of enabling work to be completed more quickly and easily, which is usually why they have developed. However, in the event of an accident, the violation of the rules is cited as a cause, the operative considered culpable warned and urged to be more careful to obey the rules in future.

Preventive action at all levels consisted largely of exhortation to be 'more careful'. Error was considered avoidable by greater effort on the part of the human operator. If 'causes' other than carelessness were apparent to the investigator, these were always close to the accident in space and time such that preventive action was restricted to the immediate circumstances of the event. This had the effect of aiming to prevent the recurrence of the same event rather than the class of events represented by that particular accident. Accidents were assumed to be determined by localised factors and the possibility that they might be useful as a data source for assessing organisation function was rarely considered. For example, boundary problems between maintenance and production departments are frequently indicated in accident occurrence (particularly in relation to fork lift trucks); accidents may reveal suboptimal relationships between the organisation and its environment; they may provide evidence of inadequacies in training programmes or supervisory practices. To regard safety as a separable and separate aspect of the function of the organisation is to overlook a valuable indicator of system functioning. However, the separation of safety training in the induction of new operatives and of Supervisors, the necessity to add guards to machines after they have been delivered, the conflict between safety and the maintenance of production levels all reinforce the view that safety is an optional extra.

Accident information The characteristics of the accident information did not

facilitate the development of strategies aimed at accident reduction. Information about reportable accidents was either in the form of a narrative description composed by the Supervisor, in absolute numbers and their rate of occurrence, or classified by 'type' and 'cause'. Narrative descriptions varied in quality and quantity because the demands of the task were not always compatible with the characteristics of the operator and because no framework was provided for recording the essential features of the event. Response to narrative description: tended to be confined to the particular event under discussion and little light was thrown on the wider issues of causation and prevention. The response to information couched in absolute numbers or rates was either exhortation "to do better in future" or expressions of satisfaction depending on whether the numbers were greater or fewer than those of the corresponding period in the previous year. Classification of accident information in terms of 'type' and 'cause' did not lead to the formulation of policies for accident reduction because of inadequacies in the taxonomies used for this purpose. The categories utilised in these taxonomies were neither logically consistent nor exhaustive.

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No provision was made in the accident reporting systems for the processing of information about minor injuries. These were made available to members of the Safety Committee of one company in the form of an exhaustive list consisting of name, injury and 'cause' of injury for each event. This method of presentation leads to trivialisation and attempts to exploit particular events for reasons not always connected with safety. Furthermore, it did not provide the Safety Officer with information of sufficient quality and quantity to detect trends, to devise strategies for the future or evaluating those of the past.

Ad hoe action Because of the inadequacy of the reporting system for

providing a firm empirical base for the development of safety policies and their subsequent evaluation, Safety Officers were obliged to adopt alternative strategies. Some attempted their own analyses of accident information which suffered from the same shortcomings as the raw information from which they were derived. Often advice for policy making was based on an intuitive understanding of the hazards associated with the work. The disadvantage of 'ad hoc' policies was the necessity, in the absence of hard evidence, to persuade management of the desirability of cooperating in the implementation of such policies and to demonstrate their effectiveness after they have been implemented. Furthermore, while intuitions may be a valuable basis for initiating policies, they may be limited in their range. Familiar situations are not usually considered hazardous. The unsystematic nature of the approach to accident information made it difficult to generate safety policies, to implement them, to sustain them and to evaluate them.

The solution

The solution was aimed at two major problems revealed by the investigation; viz, the model of accident causation (operator carelessness) and the unsystematic nature of the accident information and reduction system.

The ergonomics model The ergonomics approach to accidents is based on the

premise that what people do in a work situation is determined not only by their capabilities and limitations but also by the machines they work with, the rules and procedures governing their activities and the total environment within which the activity takes place, ie, the physical and social environment. The system made up of these elements has been called the SHEL system, (Edwards, 1972), a representation of which is shown in Fig. 1.

The three types of system resource appear as the inner circles. H stands for Hardware - the machinery; S stands for Software - the procedures, rules, regulations and customs which describe how the system works. In order to observe uniformity of vocabulary we describe the human elements as Liveware - L. These three types of system resource interact together and with their Environment - E.

Effective system operation requires that the interfaces between all the interacting elements are properly engineered to take account of the characteristics of the individual elements. System malfunction will result from a failure in

any single component, but in practice is much more likely to result from a badly designed interface.

The interfacing of pieces of Hardware is an activity familiar to engineers, who must address the problems of plugs and sockets, impedence matching, standardised power supplies and equipment rack sizes.

Analogous problems exist for the ergonomist who is concerned with the interfaces involving Liveware which, if inadequately engineered, give rise to numerous types of industrial problems.

Accidents, then, are symptomatic of a failure in the system and as such provide clues about the location of the source of failure, indicating where the mismatches occur and what kind of action is likely to be effective in reducing these mismatches. For this approach to make an impact on accident investigation and control, it was necessary for the individuals involved in these activities to modify their previous conceptions and adopt this new model for the consideration of accident causation.

Accident information system The second problem required for its solution methods

of collecting and classifying the information relating to accidents so that it could be used as a basis for devising policies aimed at accident prevention and also provide a method of evaluating these policies. In designing a solution it was necessary to take account of the features of the accident information system which were not amenable to change, eg, legal aspects, organisational aspects, and of the characteristics of those likely to use such methods.

Briefly, procedures were designed, based on the SHEL model, for the investigation of lost time accidents by

E

Fig. 1: The SHEL system showing the four interact ing components , viz:

S = Sof tware H = Hardware

E = Env i ronmen t L = Liveware

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Safety Officers and for the investigation of minor accidents by Supervisors. These consisted of questionnaires with associated documentation.

Conclusion

It is clear from the description of the SHEL model, and of the model of accident causation commonly encountered in industry, that the adoption of the SHEL model requires a radically different orientation from that in which accidents tend to be regarded as isolated events of a relatively arbitrary nature, due in the main to carelessness. It demands a major change in the way of thinking about human behaviour and of the role of the man in the system.

Here again, the inappropriateness of the natural sciences model of application is apparent. While the application of the natural sciences generally takes place through the medium of hardware, the application of ergonomics must take place initially through the medium of concepts.

The use of ergonomics depends ultimately on a change of attitude on the part of those in organisations who make decisions affecting people. This change in attitude is less likely to result from publication in learned journals than from the active involvement of ergonomists in organisations, aiming to provide real world solutions to real world problems.

References Accident Prevention and Advisory Unit 1976 Success and Failure in Accident Prevention, HMSO.

Adams, N.L. 1974 Personnel Practice Bulletin, 30.3,244-256. Using

injury statistics to set safety goals.

Chapanis, A. 1976 Engineering psychology. In Dunnette: Handbook of

Industrial and Organisational Psychology, Rand McNally.

Edwards, E. 1972 In Proceedings of BALPA Symposium: Outlook for

Safety. Man and machine: Systems for safety.

Edwards, M. 1981 A study of the feasibility of the development and

use of a systematic analysis technique for the investigation of industrial accidents. Final Report to Health and Safety Executive.

I-lartwell, N.M. 1977 Prevention of accidents by the consideration of job

design in the development of new plant. Research Report No 6245, 12/8/043, British Steel Corporation.

Hartwell, N.M., and Adams, N.L. 1977 Journal of Occupational Psychology, 50.4, 285-298.

Accident reporting systems: a basic problem area in industrial society.

Powell, P.I., Hale, M., Martin, J., and Simon, M. 1971 2000 Accidents. Report No 21, NIIP.

Tavistock Institute 1964 Social Research and a Natural Policy for Science.

Tavistock Occasional Paper No 7.

Acknowledgement

The study reported here was funded by a grant from the Health and Safety Executive.

Letter

Dear Sir, VDU Health Hazards

At a recent conference entitled 'Health Hazards of VDUs' by the Husat Research Group, Loughborough, a call was made by the participants for more research into the possible health and other risks which might arise from working with VDUs. Widespread concern was displayed at the increasing use of VDUs in various industrial and commercial aspec ts - process control, management information, stock control and clerical tasks --without a corresponding research effort being carried out to determine the nature and extent of the complaints arising from the use of VDUs and to isolate the ergonomic task factors that are posing the problems for users.

Just such research is being conducted at the Institute for Consumer Ergonomics, Loughborough where a two year project has just started with this remit. The project is sponsored by the EEC Coal and Steel Community and will be carried out in those industries and also in other

British industries which participate in terms of financial assistance or in allowing access to sites. From the research it should be possible to look generally at the incidence and severity of various kinds of discomfort and fatigue induced by VDUs and where necessary to specify ergonomic recommendations in-company for the redesign, installation and organisation of equipment and work that will be optimum within existing constraints.

We would be very interested to hear, as soon as possible, from companies thinking about VDUs and their use and who would like to contribute to the project in any way. We would also like to liaise closely with other research bodies similarly engaged.

Yours faithfully,

Margaret Stead and Howell Istance, Senior Research Officers, Institute for Consumer Ergonomics, University of Technology, Loughborough, Leicestershire LE11 3TU

Applied Ergonomics June 1981 115