The Effects of Limited Spares and Scheduled Downtime Upon The Dependability of a Simple System

Preventive maintenance and repair during a mission have an important effect on the dependability of ships´ systems. Space and weight limitations mean that not all repairs can be carried out during the mission and this limits the dependability which can be achieved. Using a simple diesel generator arrangement as an example, this paper discusses the relationships between dependability, downtime for preventive maintenance, proportion of failures repairable at sea, and equipment failure rate.