Modeling And Simulation Of Differentiated Service For Multi-location Inventory System Of Spare Parts

Under the background of informatization,the competition in the industry is becoming more and more intense,especially for some large capital-intensive enterprises.In order to maintain the leading position in the industry,each enterprise constantly seeks new ways to improve its competitiveness.During the production of enterprises,inventory is an indispensable part.As a powerful tool to ensure the normal operation of the system,reduce the risk of business downtime and improve the service level of enterprises,spare parts inventory is different from other stocks.The diversity of spare parts inventory,and the irregular demand,requires enterprises to make reasonable spares parts reserves to ensure the normal operation of production.Spare parts supply chain management is a complex issue,the difficulty lies in the different service levels of different customers,the importance of service differentiation is becoming more and more obvious.After reading a large number of relevant literature,we find that,currently,there are three main tools for differentiated service in the field of multi-loaction inventory system: critical level,selective transshipment and selective emergency shipment.Of those relative strategies researches also differ in the inventory inspection strategy,the number of warehouses,the type of spare parts and customer etc.Therefore,the scope of application varies from place to place.In order to better verify the effectiveness of each strategy in the,we mainly considers use differentiated service strategies for two types of customers in a two-level supply chain network composed of central warehouse and multi-location warehouse,and constructed three multi-location inventory models of three differentiated service strategies based on the birth and death process theory and Markov Chain.The optimal inventory level and the citical level are solved by enumeration,and the cost differences of several strategies are compared through simulation experiments,and then analyzed the sensitivity of models.At the same time,these three strategies can be extended to a series of combination strategies,we also consider the combination of different strategies as tools for differentiation of spare parts service.Based on the theory of birth and death process,we analyzed the system state transfer,and constructed three combined differentiated service inventory models,which include the critical level combined with selective transshipment model,the selective transshipment combined with selective emergency shipment model and the critical level combined with emergency supply model andsolved them.Finally,we verified the effectiveness of strategies and made a comparative analysis with previous three differentiated service strategies.