Risk-based inspection determining costs

Risk-Based Inspection. Inspection programs developed using risk analysis methods are becoming increasingly popular (15,16) (see Hazard ANALYSIS AND RISK ASSESSMENT). In this approach, the frequency and type of in-service inspection (IS I) is determined by the probabiUstic risk assessment (PRA) of the inspection results. Here, the results might be a false acceptance of a part that will fail as well as the false rejection of a part that will not fail. Whether a plant or a consumer product, false acceptance of a defective part could lead to catastrophic failure and considerable cost. Also, the false rejection of parts may lead to unjustified, and sometimes exorbitant, costs of operation (2). Risk is defined as follows ... 

Dollar values for each consequence were determined in agreement with operations, engineering, and inspection personnel based on costs of past failures and loss of production. The results of the risk assessment were then used to identify which equipment and piping were to be replaced during the next refinery FCCU turnaround. 

Condition assessment of aU pipelines in a system may take years because of operational constraints, logistical issues, and cost. It is therefore important to determine priority, sequence, and long-term schedules for pipeline inspection. These decisions are usually driven by potential consequences of failure and perceived pipeline condition based on the history of performance and other pipeline risk factors. There are two important components in determining the risk associated with a pipeline and therefore the pipeline criticality and inspection priority (1) the likelihood of pipe failure and (2) the consequence of failure, should it occur on a given pipeline (Zarghamee et al., 2012). 

---