an inventory–scheduling model for supply chain of construction project

one of the important problems in project management is lack of available resources in proper time at project site that leads to lack of project implementation in due date. this problem may be lead to time delay in sending resources from suppliers and related origins in supply chain to project site. therfore, to better resources managmenet and also the improvement of supply chain condition, the time delay problem in resources supply can be solved by determining the optimal quantity of order in supply chain based on project constraints and required time for implementation of supply chain activities. accordingly, in this paper a mamathemical model is proposed for determining the optimal quantity of orders and activities duration of supply chain, in which the total holding cost in project site and also supply chain cost are minimized. the mentioned model is first linearized and then by using the numerical examples, the results analyziz are presented.