Assessing safety functions – results from a case study at an industrial workplace

This study is concerned with how safety characteristics at industrial installations can be modelled and evaluated. The starting point was the concept of safety function, which is defined as a technical, organisational or combined function that can reduce the probability and/or consequences of accidents and other unwanted events in a system. A tentative theoretical framework has been developed, which has been applied in a new method called Safety Function Analysis. A workplace in process industry was analysed in the form of a case study. One result of the application was a model of safety functions in the workplace, including 54 functions. These have been evaluated, and system improvements have been proposed. A detailed comparison was made with the results of two other methods for safety analysis— Deviation and Energy analysis—applied to the same workplace. Safety function analysis gave essential supplementary information, and especially supported improvement of management issues, both formal and informal. It is concluded that the safety function concept worked well in the practical analysis of safety in the studied system. There is a need for further improvement of the theoretical framework, and of the method.