2002 年 2002 巻 238 号 p. 238_173-238_184
This paper addresses an quantitative procedures in decision-making process to determine whether marine machinery that have been entering the wear-out phase need to be replaced, or only demand preventive maintenance action. Components must be replaced if they cannot attain the minimum requirement of reliability index (RI) and availability index (AI). In the case when the preventive maintenance is the decision to be taken, this paper also recommends the optimum interval between maintenance based upon the minimum total cost (the objective function) rendered by the decision. An assumption is taken in which onboard maintenance is not possible; hence penalty cost are induced until the components are repaired in yard/port and become operable. Premium Solver Platform (PSP), a spreadsheet modeling tool, is utilized to model the optimization problem. Constraints, which are considerations to be fulfilled, become the director of this process, and a minimum and a maximum value are set on it to give the working area of the optimization process. The model takes a finite and n-equal interval between maintenance, and the increase of operational cost and maintenance cost due to deterioration is taken into account. An analysis on main engine cooling pumps of a ship is adopted as the case study.
