The objective of this paper is to describe and evaluate a scheme of engineering-economic analysis in determining a ship's machinery performance and its maintenance management scheme. The machinery performance is assessed by means of Continuous MARKOV analysis by obtaining its performance indices such as Reliability, Availability and Maintainability (RAM). Since the problem of ship and marine machinery operation can be represented as a multi-variable and multi-constraint engineering-economic problem, then a multiple constraints optimization scheme can be utilized to find the most appropriate maintenance management scheme. The main engine cooling system of a ship is taken as the object of the study case. It is conclusively found that this kind of simulation can be used not only to determine the maintenance management scheme, but also as an appropriate tool in evaluating and selecting alternative machinery designs.