As part of the research on high speed radial diesel engines, an analysis had been conducted on the use of the operating systems of the missile boats and comparison of the results with the manufacturer’s recommendations. A graphic model had been
set up (block – diagram) on high speed radial ship diesel engine. On the basis of research and empirical data collected on defects which cause the inability to use the engine, the total exploitation reliability of complex technical system and the statistical characteristics of the life of the system had been defined, starting from the assumption that the life of the technical system tested belongs to the Weibull distribution. Research results had been achieved by means of the simulation method (the simulation model) and then were tested with the use of the contemporary computer applications. By defining the levels of operational capability, the levels of reliability had eventually been set up and they need to be ensured through modified maintenance procedures so that the investigated technical system could meet the required criteria. In the research of new samples, the needed intervals of preventive replacement of critical system parts will be determined so that the demanded reliability would be ensured.