Spare Parts Stock Optimization Abased On Reliability

The reliability of production systems is an important indicator of market competition now. Whether the production equipment run normally is the important condition of ensuring the stated reliability of production systems. And spare parts immediately influence the maintenance, overhaul and emergency repair work of the equipments, therefore managements of spare parts are closely related with enterprise's regular production and the economic efficiency directly, that is, the spare parts are playing the very important role to the reliability of production system. As a result of large and medium-sized manufacturing enterprises have a large number of machines and equipment, and therefore non-production materials are consumed in large quantities of spare parts, and the regularity of spare parts demand is bad, having quite randomicity, and it is difficult to predict, so the management of spare parts often troubles the managers of the companies. If we reserve too many spare parts, production is easy to guarantee, but takes the enterprise the massive floating capital; If the reserve is too small, the production is unable to guarantee, causes the equipment in vivo domestic product, loses the market opportunity, even creates the heavy economic loss. Many Enterprise's spare parts storage quantities reach as high as the business equipment investment above 10% in our country, and because of the renewal of equipment each year, there will be a certain amount of spare parts for scrap, result in the waste of a lot of money.In this paper, firstly we do the detailed introduction of the current status of the spare parts management and reliability of theoretical knowledge and so on, secondly from the production systems to ensure the reliability of indicators of a certain objective, to find the optimal spare parts inventory storage. And divided spare parts into repairable and unrepairable parts, to unrepairable parts, use renewal process mathematical model to find the most superior reserve in the condition of ensuring the certain reliability; to repairable parts ,use M/M/n/m + N/m and M/M/1/m + N/m queuing model in queue theory and m|- / G(m + N) voting system model of Markov repairable system, studying the series system and parallel systems of repairable parts respectively, then get the most superior reserve in the condition of ensuring the certain reliability.Finally, we summarized the main research results, further work on the direction of the research a brief outlook and discussion.