We propose a tactical model which integrates the replenishment decision in inventorymanagement, the allocation of products to warehousing systems and the assignment of products tostorage locations in warehousing management. The purpose of this article is to analyse the valueof integrating...

We consider the single item lot-sizing problem with capacities that are non-decreasing overtime. When the cost function is i) non-speculative or Wagner-Whitin (for instance, constantunit production costs and non-negative unit holding costs), and ii) the production set-upcosts are non-increasing...

Providing a good formulation is an important part of solving a mixed integer program. We suggest to measure the quality of a formulation by whether it is possible to strengthen the coefficients of the formulation. Sequentially strengthening coefficients can then be used as a tool for improving...

We consider the single item lot-sizing problem with capacities that are non-decreasing over time. When the cost function is i) non-speculative or Wagner-Whitin (for instance, constant unit production costs and non-negative unit holding costs), and ii) the production set-up costs are...

We examine a variant of the uncapacitated lot-sizing model of Wagner-Whitin involving sales instead of fixed demands, and lower bounds on stocks. Two extended formulations are presented, as well as a dynamic programming algorithm and a complete description of the convex hull of solutions. When...

Mixed-integer rounding (MIR) inequalities play a central role in the development of strong cutting planes for mixed-integer programs. In this paper, we investigate how known MIR inequalities can be combined in order to generate new strong valid inequalities. Given a mixed-integer region S and a...

We consider the problem of designing a 2-stations Automated GuidedVehicle System (AGVS). The AGV System consists of a pool of vehicles that transports products from one station to the other station through an unidirectional guidepath. We seek a model to estimate the minimal number of vehicles...

We examine the polyhedral structure of the convex hull of feasible solutions of the capacitated facility location problem. In particular we derive necessary and sufficient conditions for a family of "effective capacity" inequalities to be facet-defining, and further results on a more general...