Assesment of operation of ship main diesel engine using the theory of semi-Markovian and Markov processes

Operation of ship propulsion system is associated with realization of definite operational goals. If to elements of the system the operational reliability strategy could be applied, the situation would be very simple as existing conditions would unambiguously determine application of means being on hand. However decision to reject application of the strategy (even if hypothetical) becomes obvious with a view of necessity of ensuring an acceptable level of safety to ship and environment as well as presence of associated formal and legal limitations. Therefore complexity of operational reality makes that means intended for operation may be used in various ways. Objectivity and rationality in making decision, assumed optimal in given conditions, forces to apply an evaluating (quantitative) approach to the problem, hence to search for such their parameters (indices) which, in a given decision situation, can be deemed most adequate. To precisely determine the task it is necessary to specify also its duration time, apart from conditions in which it will be realized. When considering propulsion engine, i.e. the main element of ship propulsion system, especially important becomes not only the problem which amount of energy could be at one's disposal but also within which time interval it could be delivered. Therefore apart from applying the commonly used reliability indices, it seems sensible to consider the operation in such evaluating approach as it could be determined by energy and time simultaneously.