ABSTRACT
Judging Safety Performance In order to be able to judge safety performance and to communicate it to somebody else via the safety case or other safety report, some scale of safety measurement needs to be defined, some idea of good and bad needs to be set as a benchmark. With the wide variety of systems, procedures and materials in industry and the public domain, a scale of safety is needed to provide a measurable approach to the achievement of safety and to the exposure to risk. Safety as a property of a system is qualitative, you could not say that a particular system was ‘10 safe’, or that something was 50% safe. These expressions have no meaning until they are given a logical framework of reference or a measurement scale. In this way safety data collected can be subjected to a form of systematic analysis, which can turn the data into evidence directed towards judging safety performance. The data can be quantitative or qualitative, as long as the measurement system in place is geared to be able to handle either or both. But some important questions remain. How bad is bad? How safe is safe enough? Who actually says this is bad and that is not? The who is you. Public perception of risk is the key to safety. If something is thought of as being terribly dangerous, public opinion calls for action, legislation and prosecution. Our elected representatives with authority in these areas duly provide laws, working practices and procedures to be followed. They will specify things that can and cannot be done, and will apply the weight of the local, federal or national law if anything is breached. I know it’s not quite as simple as that, but that is the general trend. At the level of the individual, the perception of risk is a result of many different factors, as opposed to what might be thought of as rational judgements based on severity and likelihood of an accident. Some reasons for this departure are systemic biasing of risk information, personal experience, the use of psychological shortcuts and the way that hazard and accident information is presented to a person, including media coverage. These reasons have greater effect when the temporal separation of cause and effect is large and the immediate consequences of an action are not demonstrated by a direct link. The relationship between public perceived risk / safety and actual risk / safety is complex and controversial. For more discussion in this area please refer to research undertaken by the UK Health and Safety Laboratory [HSL 2005].
