Probabilistic risk assessment is an attempt to quantify design and or manufacturing risks associated with use of a specific product or technology. Risk assessment consists of three main elements: scenarios, frequencies and consequences. Scenarios entail a list of all of the possible sequences of events. Frequencies represent the relative probability the scenario will occur whereby consequences are the expected outcome given the scenario does in fact happen. This paper, taken from a design perspective, will discuss a variety of risk assessment tools including event sequence diagrams, fault trees and maximum likelihood estimates. Application techniques will be explored allowing product-engineering teams to quantify product risks, subsequently determining the likelihood of product success.