Supplier selection is a multi-criteria problem which includes both tangible and intangible factors in these problems if suppliers have capacity or other different constraints two problems will exist: which suppliers are the best and how much should be purchased from each selected supplier? The objective of this paper is to present an integrated model and a supporting approach for effective ...

  The importance of reliable supply is increasing with supply chain network extension and just-in-time (JIT) production. Just in time implications motivate manufacturers towards single sourcing, which often involves problems with unreliable suppliers. If a single and reliable vendor is not available, manufacturer can split the order among the vendors in order to simultaneously decrease the supp...

We study a single-period inventory control problem with two independent suppliers. With the first supplier, the buyer incurs a high variable cost but negligible fixed cost; with the second supplier, the buyer incurs a lower variable cost but a positive fixed cost. At the same time, the ordering quantity is limited. We develop the optimal inventory control policy when the holding and shortage co...

We consider a make-to-stock supplier who operates a production facility with limited capacity. The supplier receives orders from customers belonging to several demand classes. Some of the customer classes share advance demand information with the supplier by announcing their orders ahead of their due date. However, this advance demand information is not perfect because the customer may decide t...

We study a supply chain with two suppliers competing over a contract to supply components to a manufacturer. One of the suppliers is a big company for whom the manufacturer’s business constitutes a small part of his business. The other supplier is a small company for whom the manufacturer’s business constitutes a large portion of his business. We analyze the problem from the perspective of the ...

GOKCE, MAHMUT ALI. Optimization of Sourcing Decisions in Supply Chains. (Under the direction of Dr. Russell E. King, Dr. Jeffery A. Joines, and Dr. Michael G. Kay.) Sourcing decisions in supply chains traditionally are made solely based on cost considerations. Typically sourcing models or decision-making procedures are either ad hoc or proprietary. In this dissertation a meta-heuristic-based op...

We study the important problem of how a supplier should optimally share the consequences of demand uncertainty (i.e., the cost of inventory excesses and shortages) with a retailer in a two-level supply chain facing a finite planning horizon. In particular, we characterize a multiperiod contract form, the promised lead-time contract, that reduces the supplier’s risk from demand uncertainty and t...

In practices, the supplier may simultaneously offer the customer: (1) a permissible delay in payments to attract new customers and increase sales, and (2) a cash discount to motivate faster payment and reduce credit expenses. Since all cash outflows related to inventory control that occur at different points of time have different values, we use the discount cash-flow (or DCF) approach to esta...

Robust supplier selection problem, in a scenario-based approach has been proposed, when the demand and exchange rates are subject to uncertainties. First, a deterministic multi-objective mixed integer linear programming is developed; then, the robust counterpart of the proposed mixed integer linear programming is presented using the recent extension in robust optimization theory. We discuss dec...