Risk Based Inspection API 580 - API 581 RBI is an often-used word in inspection.  RBI stands for Risk Based Inspection.  RBI tries to answer the following questions - 1. Which part should I expect first?  2. Which part is the most critical? 3. How should I start inspecting it first? 4. Where is the highest risk of failure?  5. Where is the order of risk? PoF is Probability of Failure . This is answered by the following questions - 1. How likely is the failure to occur? 2. How frequently will the failure occur? 3. Is there an approximate time to failure or the number of failures per time? CoF is Consequence of failure Consequence defines how dangerous the failure will be to the resources around it. This implies the following questions - 1. What kind of failure will it be? 2. Will it damage the components? 3. Will it be harmful to human life? 4. Will it affect/contaminate the environment? The risk is calculated as follows - Risk =  PoF x CoF The number designated to Pof and Cof depends o