Minimizing mission cost for production system with unreliable storage

Abstract

Considerable research efforts have recently been devoted to the reliability analysis and optimization of production systems with product storage. The existing models, however, failed to address a crucial design factor of cost. This paper makes contributions by modeling the expected mission cost (EMC) of an imperfect production system with storage subject to failures during uploading and downloading processes. To perform a successful mission, the system must meet a certain demand during a specified mission time. The EMC modeled encompasses operation and standby cost of the production unit, downloading and uploading cost of the storage, cost of losses associated with the failure of the production unit and storage, as well as penalty cost associated with the mission failure. The optimal EMC problem is formulated and solved, which determines the scheduled storage uploading time to minimize the EMC. A detailed case study of a coal feeding system is conducted to demonstrate the proposed probabilistic evaluation method and influences of different model parameters on the mission success probability and EMC as well as on the optimization solutions. The advantage of using the production storage is also illustrated through a comparison to a dual-production unit system without storage.