On the Use of Performance Shaping Factors (PSF) for Risk Analysis in Cold Climate Regions

Cold regions have their unique hazards such as hypothermia and frostbite. Hence, these hazards must be taken into account very early in the design phase. Moreover, risk analysis approaches should be updated to take into account the specific hazards of the Cold Climate region. There can be a high dependence between different cold region hazards and a combination of failures can happen during an extreme weather phenomenon. Therefore, the assumptions of independence among the risk factors must be critical examined and the chain of events should be more focused. Sometimes, increasing the reliability will lead to more complex designs. Adding to the complexity of the system, could cause the human error to be increased significantly. Hence, increasing the reliability of a plant or a process by adding complexity, does not necessarily lead to increasing the safety. In this study an analysis of the reliability of a ventilation system in a moderate climate region is used as reference case for a risk analysis of a winterized ventilation system in a Cold region. In the analyses, performance-shaping factors are assessed, stressing the need of a risk analysis in which human and environmental factors are especially examined.