Oğuz Solyalı

TL;DR: This work considers a two-level vendor-managed system in which external demand occurs only at a retailer and a supplier replenishes the retailer employing an order-up-to S policy over T periods and presents an O(T^3) algorithm to coordinate the system when S is known.

TL;DR: This study proposes a branch-and-price algorithm that solves instances that could not be solved in one hour CPU time in less than a second and is able to solve large-scale instances in reasonable times which make it a computationally viable tool for decision-making.

TL;DR: In this article, the serial lot sizing problem with backlogging in two-level supply chains is considered, where the goal is to determine when and how much to order at a warehouse and ship to a retailer over a T-period planning horizon so that the external known demand occurring at the retailer is satisfied and the total cost at all levels is minimized.

TL;DR: A strong mixed integer program formulation is proposed for the problem with zero and nonzero initial inventories at the warehouse and Computational results with a state-of-the art solver reveal that the formulations are very effective in solving large-size instances to optimality.

TL;DR: An effective lower bounding procedure based on solving a new integer programming model of the shift minimization personnel task scheduling problem outperforms those existing in the literature and consistently and rapidly yields high quality lower bounds that are necessary for the decision makers to assess the quality of the obtained schedules.