مدل مقدار تولید اقتصادی با تثبیت محموله از آیتم های با کیفیت ناقص:اول یادداشت

In this note, we correct some typos that appeared in Yassine et al. {Yassine, A., Maddah, B., Salameh M., Disaggregation and consolidation of imperfect quality shipments in an extended EPQ model, International Journal of Production Economics 135 (2012) 345–352}, specifically, for one of their models that considered consolidating shipments of imperfect quality items across multiple production cycles. In addition, we present a heuristic approach to find a good solution for this model. The performance of heuristic solution is illustrated with numerical examples.

In order to capture the real situation, numerous studies have modified the traditional economic order/production quantity (EOQ/EPQ) models to include imperfect quality items, and proposed different ways to handle them. For a detailed review and discussion of the related literature, we refer the readers to Khan et al. (2011). For up-to-date research, see e.g. Rezaei and Salimi (2012), Hsu and Hsu (2012), etc. Recently, Yassine et al. (2012) extended the EPQ models to address the issues of shipping the imperfect quality items through disaggregating (into smaller batches within a single production run) or consolidation (across multiple production runs) of imperfect quality items. We have read the paper with a considerable interest. However, we found some typos in their consolidating shipments model, where one of the decision variables (namely the number of production cycles (nc) between two consecutive shipments of imperfect quality items) is determined through solving a cubic equation. We also found some typos in the numerical results. This note rectifies the above mentioned results and presents an easy-to-compute heuristic solution for nc. Numerical experiments are carried out to illustrate the performance of this solution.

This note corrected some typos that appeared in Yassine et al.'s (2012) consolidating shipments model. It also provided a heuristic solution with closed-form expression for determining the near-optimal number of production cycles. Numerical results indicate no optimality gap of the heuristic in the tested cases.