Communication and Risk Awareness

Awareness of the risk in the controlled process is a major component of safety-related decision making by controllers. The problem is that risk, when defined as the severity of a loss event combined with its likelihood, is not calculable or knowable. It can only be estimated from a set of variables, some of which may be unknown, or the information to evaluate hkelihood of these variables may be lacking or incorrect. But decisions need to be made based on this unknowable property. 

In the absence of accurate information about the state of the process, risk perception may be reevaluated downward as time passes without an accident. In fact, risk probably has not changed, only our perception of it. In this trap, risk is assumed to be reflected by a lack of accidents or incidents and not by the state of the safety control structure. 

When STAMP is used as the foundation of the safety program, safety and risk are a function of the effectiveness of the controls to enforce safe system behavior, that is, the safety constraints and the control structure used to enforce those constraints. 

Poor safety-related decision making on the part of management, for example, is commonly related to inadequate feedback and inaccurate process models. As such, risk is potentially knowable and not some amorphous property denoted by probability estimates. This new definition of risk can be used to create new risk assessment procedures. 

While lack of accidents could reflect a strong safety control structure, it may also simply reflect delays between the relaxation of the controls and negative consequences. The delays encourage relaxation of more controls, which then leads to accidents. The basic problem is inaccurate risk perception and calculating risk using the wrong factors. Ihis process is behind the frequently used but rarely defined label of complacency. Complacency results from inaccurate process models and risk awareness. 

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