Supply chain modelling using fuzzy sets

This paper considers a production supply chain (SC) with all facilities in a serial connection. The SC includes inventories and production facilities between them. It is assumed that the SC operates in an uncertain environmen t. Uncertainty is associated with: (1) customer demand, (2) supply deliveri es along the SC and (3) external or market supply, Uncertainties are descri bed by vague and imprecise phrases that are interpreted and represented by fuzzy sets. The SC fuzzy model described in this paper is developed to determine the or der quantities for each inventory in the SC in the presence of uncertaintie s, that give an acceptable service level of the SC at reasonable total cost . Two control concepts of the SC are treated: (1) decentralised control of each inventory and (2) partial coordination in the inventories control. A s pecial purpose simulator has been developed for examining the dynamics and performance of all the parts of the SC and the SC as a whole. Various simul ation tests have been carried out to assess particularly the effects of unc ertain external supply on the SC service level. Different approaches to imp rove SC performance in an uncertain environment have been simulated and ana lysed. (C) 1999 Published by Elsevier Science B.V. All rights reserved.