Mathematical modelling to improve Rolled Throughput Yield in a supply chain

The outspread of supply chains competition entails inevitable application of quality improvement methods, such as Six Sigma. It is less than a decade that Six Sigma methodology has entered the supply chain scope; however, researches undertaken in this field have massively increased. Most of these research works have been done towards the application of the Six Sigma method for supply chain improvement, yet nothing has been done about suitable entity selection in supply chain for improvement. The purpose of this article is to propose a method for individual entity selection in the supply chain. Accordingly, a mixed integer non-linear programming model is presented that shows which supply chain entity should be selected, and how much to improve, in order to maximise financial benefit. This article also presents new comprehensive criteria based on the previous approach, which can measure the performance of the supply chain. Moreover, the ability of the proposed criteria is shown through a numerical example. Finally, the optimisation model was applied for selecting individual entity in tweedy supply chain in order to illustrate the capability of the model. In addition, sensitivity analysis is carried out on the parameters of the model.