THE IMPACT OF SOCIAL FACTORS ON ACCEPTABLE LEVELS OF SAFETY INTEGRITY

Abstract

The paper emphasises the inherently subjective nature of the concept of safety, whilst accepting the need for some objectively based means of measuring it. The concept of levels of safety is introduced. The combination of risk and consequence as a means of determining required safety integrity as described in IEC 65A(Secretariate)-94I is referred to. Possible means of combining values for risk and consequence to give a meaningful measure of safety integrity requirement are discussed. The potential benefit of the application is introduced as a contributor to the required safety integrity and possible means of incorporating this factor are discussed. A range of social factors which contribute to risk/benefit/consequence and a means of combining these to produce an ‘objective’ measure of the level of safety integrity which should be required of a system are proposed. This combination draws on the ideas presented in DIN V 19 251.