Citation

Borse E. J. Occup. Accid. 1979; 2(3): 227-243.

Copyright

(Copyright © 1979, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

A methodology called "accident analysis" is proposed which enables the total level of safety of a specific type of industry or overall layout to be estimated. The methodology links the total level of safety to every individual accident that can occur and the accidents probability distribution with magnitude. The methodology has been related to design of offshore platforms with particular reference to drilling/production platforms with living quarters. A list of Design Basis Accidents for offshore platforms is presented where the accidents are listed according to the estimated probability of occurrence. Based on this list, it is shown how three parameters: probability distribution with magnitude of each DBA; probability of one DBA to initiate others, and when requested; consequence distribution and maximum consequences (i.e., to the surroundings); can describe each DBA. The DBA can therefore be compared to ensure a comparable level of safety and be related to the total level of safety.It is shown that risk based on magnitude of an accident is the only valid basis for design criteria and that risk based on consequences implies that an industry is designed to a "legalized fatality rate".Protective measures to resist an accidental load depend on the degree of protection demanded. Design Basis Accidents must therefore be related to whether they should be complete DBA (to a given level), whether only certain effects of the accidents should be considered or whether the effect of the accident should only be delayed. Residual risk and residual load are introduced to account for unpredictable risks and loads. Accident analysis of a specific type of industry will give design criteria on which a risk assessment of a specific design can be based, and estimate safety levels to which a risk assessment can be compared.