Optimal inventory modeling of multi-ECHELON system for aircraft spares parts

Owing to the expensive and sporadic demand nature of aircraft spare parts, the stock level of spare parts was difficult to confirm. How to maximize the availability of the aircraft fleet with cost constraint for spare parts was an important issue for airlines. A multi-ECHELON inventory model based on METRIC (Multi-ECHELON technology for recoverable items control) was proposed by allocating spare parts among the bases of airlines in this study. The model based on system approach instead of item approach to determine aircraft spare parts stock level in a multi-ECHELON system. First, the key system measure was selected, then, the Negative binomial distribution was employed to more accurately reflect the variance in part failure processes when the value of variance-to-mean ratio was bigger than one, Next, the marginal analysis method was applied to find the optimal position of spare parts among bases and depot, finally, two examples were given and the first one showed that the negative binomial distribution was more reasonable than Poisson distribution to describe the non-stationary demand process. The second one showed that the models in this paper were engineering applicability for airlines and could provide an effective theoretical and technical support. © 2013 Asian Network for Scientific Information.