Integrated allocation of warship reliability and maintainability based on top-level parameters

• Integrated method was proposed to the warship reliability allocation.
• Solving the synergistic problem between reliability and maintainability parameters.
• A multi-stage model was established to describe the mission reliability of warship.
• Allocation results provided a basis for understanding the reliability design goals.

In warship design and development, reliability should be allocated from top-level requirements to subsystem and equipment levels using an effective allocation method. Mission reliability and inherent availability are top-level reliability parameters of a warship; these parameters do not only involve factors of reliability, but also those of maintainability. Therefore, extensively used reliability allocation methods cannot address the reliability allocation of warships. A warship is a typical repairable system. Based on warship characteristics, this study proposed an integrated reliability and maintainability allocation method for warships. In the comprehensive allocation process, reliability and maintainability factors that affect the top-level reliability parameters of a warship were measured quantitatively. The synergistic principle of the reliability and maintainability indexes was discussed to solve the synergistic problem between the reliability and maintainability parameters of a unit. The top-level reliability indexes of a warship were reasonably allocated to all levels using optimisation methods. The proposed method is not only suitable for warship reliability allocation but also for other complex repairable systems.