One semi-quantitative risk analysis technique used is Risk Ranking. This technique involves identification of hazardous events that could occur at a facility, and estimation of the possible consequences and probability of occurrence of each event. Consequence assessment can be done quantitatively (with Consequence Analysis) or qualitatively. The probability estimates can be based on field inspections of the equipment that is the subject of the study, or extensive checklists that rank the various pieces of equipment according to factors known to affect the likelihood of equipment failure. The product of this type of study is a list of equipment or plant areas ranked according to the level of risk they pose. Studies of this type are a cost- effective way to determine which areas of your processing facility, pipeline, or operation pose the highest risk, allowing you to prioritize your risk reduction efforts.
Risk Matrix used in Risk Ranking