Chapter 28 - Probability and Risk Based Inspection Planning

Abstract

This chapter discusses probability and risk-based inspection planning. Risk assessment can be used as a valuable tool for assigning priorities among inspection and maintenance activities. This chapter shall present the following: concepts of risk-based inspection, reliability updating theory for probability-based inspection, risk-based inspection examples, risk-based optimum inspection. It is concluded in this chapter that the inspection planning is dependent on the consequence of failure, corrosion rate, ship age, and probability of detection. The “optimum” inspection program should begin with the design of the structure proceed through the life of the structure, and conclude with its scrapping. The optimum inspection program should include not only the hull structure, but its equipment, and its personnel as well. In general, the dimensions of risk can be considered by the categories of personnel risk, fatality risk, impairment risk, environmental risk, asset risk, etc. This chapter discusses reliability updating theory for probability-based inspection planning. Fatigue failure is defined as the fatigue crack growth reaches the critical size. The methodology presented could be extended to risk-based inspection. The likelihood of failure may be divided into three categories, which is mentioned in this chapter. The vessel factors can be divided into two categories: design factors and condition/maintenance factors. The “optimum” inspection method can be proactive or it can be reactive. Some of the general objectives of an inspection data system are described in this chapter including collect inspection data, store the data, and provide means for logic inspection data management.