Applying Axiomatic Design to Risk Assessment

As the complexity of our society increase, managing risk is an important task in maintaining healthy and sustainable societies. Risk assessment is a widely used method to identify events associated with high probability of occurrence and severe consequences. Although simple and easy to understand, risk assessment is over-simplified with a single estimate of occurrence probability and a single severity evaluation of each event. Axiomatic design (AD) decomposes an overall functional requirement (FR) into a set of element FRs. Although an uncoupled design is ideal with each FR mapping to a single design parameter (DP), a design, in many cases, is coupled and one or more single FRs may depend on multiple DPs. This study shows how we can apply the design equation formulation of AD to risk assessment by identifying the failure probability of each DP, estimating the severity of not meeting each FR, and then calculating the risk associated with each FR. The method identifies improvement on which DP is most effective in reducing the overall system risk. Our analysis also shows how unwanted design interference can cause unexpected serious negative consequences. The designer is encouraged to apply AD to recognize design interference and spend efforts in removing them before production.