Risk-Based Optimization of Inspection Planning in Ships

There is competitive pressure on industry to look for cost-effective approaches to manage ships such that they remain fit for service. Inspection provides information of the state of a structure or equipment and is thus a vital input to this process of maintaining ships. This paper presents an innovative and a pragmatic application of risk-based principles for planning inspection as applied to the ship hull structure. The application of this approach has the potential to reduce the operation and maintenance costs of ships and increase their reliability. Current approach to inspection of ships is heavily influenced by time-based (class) rules. The aim of this paper is to demonstrate a methodology using information generated by class inspection and/or historical operational data to optimize inspection such that the risk of failure of a structure and the cost of such inspection is minimized or within user-specified acceptable limits. The proposed inspection planning methodology does not purport to do away with class inspections-it supplements these. The paper describes work-in-progress on research undertaken for a project with the acronym RISPECT (Risk Based Expert System for Through-Life Structural Inspection, Maintenance, and New-Build Structural Design) under the auspices of the European Commission's Framework 7 program.