The Effectiveness of ``On-Board'' Maintenance

``On-board'' maintenance for offensive weapons systems and its relationship to the allocation of spare parts is discussed. A method for the selection of ``on-board'' spare parts is given and an expression for the increase in subsystem reliability through ``on-board'' repairs is derived. The concepts of effective reliability, combat effectiveness, and criticality of spare parts are examined. Curves obtained from a hypothetical but realistic maintenance situation show the given relationships between the criticality and the weight and volume of spare parts. These relationships provide a basis for decision on the allocation of spare parts for improving combat effectiveness through ``on-board'' maintenance.