Abstract
In the recent competitive market, benefits from plant operation and maintenance are the crucial target in asset management. Risk-based engineering (RBE) could be an effective tool for the purpose, with various approaches proposed for optimizing maintenance planning. One approach is the probabilistic risk assessment (PRA) which defines the risk as the product of probability of failure (POF) and consequence of failure (COF). Taguchi method is introduced into the optimization procedure with the net income gain function as the operation income subtracting maintenance cost and risk cost. S/N ratios are calculated using L9 orthogonal array of net income gain function for several control factors and noise factors. Noise factors include material creep life scatter which is calculated from the NIMS creep data sheet. The trial calculation results for assumed high temperature power plant show that this combined approach of PRA and Taguchi method is effective for selecting robust and optimum plan for operation and maintenance of plant against all case of noise factors.
