Alternative accident-prevention approaches

There is no simple and uniform way to achieve a high safety standard. Throughout the book, we will see how different approaches contribute to our understanding of why accidents occur and how to prevent them. The intention is not to search for a unifying synthesis but rather to show the distinct characteristics of each approach and to analyse the contributions from each of them. To demonstrate the variety and to help the reader in recognising the differences, we will here look into four different approaches, each convincing from its own standpoint. We will later develop some of them further and present alternative ones to get a more comprehensive understanding. 

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There was an increased focus on the identification of causal factors in accident investigations by use of checklists. The supervisors making the investigations had, however, a tendency to choose causal-factor alternatives that were not possible to verify and that brought about minimum obligations to carry out remedial actions. The same lack of variety in the selection of remedial actions was observed in this oil company as in the six Swedish companies a decade before. There was no obvious link between the types of causal factors that had been identified and the selection of remedial actions. It follows that the supervisors did not use the rational approach shown in Figure 6.6 in their decisions on accident prevention. 

Any specific realization of this general systems engineering process depends on the engineering models used for the system components and the desired system qualities. For safety, the models commonly used to understand why and how accidents occur have been based on events, particularly failure events, and the use of reliability engineering techniques to prevent them. Part II of this book further details the alternative systems approach to safety introduced in this chapter, while part 111 provides techniques to perform many of these safety and system engineering activities. 

An alternate approach is a proactive one. As shown in Figure 3-6, the preventive strategy starts with analysis. The aim is to identify all of the factors that can lead to accidents and the combinations of those factors. Preventive strategies come from the analysis. The approach seeks to avoid having accidents at all. Several detailed strategies build on this approach. 

If an accident cannot be anticipated or expected by anyone, then it is indeed due to chance or to forces beyond our understanding (Figure 17-1). In that case, the term accident causation is an oxymoron. Alternatively, if we accept the notion that traffic accidents are not chance events or acts of God, then they can be predicted and prevented. This rationale led the U.S. National Highway Traffic Safety Administration and the journal Nature to replace the term accident with the term crash . With this approach we assume that if a person with some relevant expertise has at his or her disposal all of the necessary data immediately before an accident happens, he or she can foresee the accident. From the perspective of that expert the accident can or could have been avoided. The knowledge that is available to our mythical expert is what we seek in our attempts to understand the reasons or causes of accidents. 

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