An integrated model for solving the multiple criteria ABC inventory classification problem

In this paper, we present an integrated version of the Ng model and Zhou and Fan model [W. L. Ng, A simple classifier for multiple criteria ABC analysis, European Journal of Operation Research, 177 (2007) 344-353; P. Zhou & L. Fan, A note on multi-criteria ABC inventory classification using weighted linear optimization, European Journal of Operation Research, 182 (2007) 1488 1491]. The model that Ng [1] offered, hereafter called the Ng-model, in spite of its advantages may lead to a situation in which the weights of some criteria in relation to an item would not play any role in determining overall score that item. Also, the scale transformation that he applied for transforming the measures of items under criteria into interval 0-1 is not suitable for the small-scale measures. On the other hand, for the R inventory item, the Zhou and Fan model [2], hereafter called the ZF-model, should be solved through a linear optimizer 2R times in which an inventory manager mighthas no any background in regard with optimizer. Furthermore, when number of items is large, the computing time would increase. Therefore, in order to remove drawbacks of both the approaches, an integrated model is presented in which objective functions are the same ZF-method but its constraints is similar to Ng model. At last, results obtained from applying the proposed model in an illustrative example are compared with Ng and ZF-models.