Study on optimal inventory strategy for worn spare parts on the Chinese space station

The demand for spare parts on the Chinese Space Station is always uncertain, meaning that an inventory for parts is difficult to confirm. A key problem on the space station is how to minimize the expected backorder number with limited resources. In this paper, a multi-ECHELON inventory model for worn spare parts based on the METRIC (Multi-ECHELON technology for recoverable items control) model was proposed to solve this problem. First, the principle of the METRIC model was analyzed and some of the hypotheses of the traditional METRIC model were adapted to form a new METRIC model known as GENE-METRIC Next, the marginal analysis method was applied to find the optimal position and number of spare parts needed. Finally, a numerical example was given to illustrate the use of the new GENE-METRIC model. The paper argued that the new GENE-METRIC model could provide a quantifiable approach to confirm the stock level of worn spare parts and could therefore be used to inventory and allocate the worn spare parts as needed for the Chinese Space Station.