Production planning with lot-sizing and scheduling in industries where the cleaning times depend on the sequence of the products can be modelled as a mixed integer problem. However, this problem is very hard, and even small instances cannot be solved exactly in a reasonable time. We propose a division of the whole production planning problem into its two subproblems, and to solve each them inde...

The classical lot, sizing model deals with economic lot sizing for production in a deterministic framework. In real life, various forms of uncertainty affect the production. These include machine breakdown, quality variations, and so on. This paper develops a model with unreliable production systems and under alternative repair option strategies. @ 2000 Elsevier Science Ltd. All rights reserved...

Often lot sizing and scheduling models have neglected the consideration of influence of product life cycles (PLCs). But, accordingly as desirable in a firm’s production strategy, decisions of lot sizing scheduling may have to respond to the stage changes in a product’s life cycle. In this paper, we propose an extension of the lot sizing scheduling, the multi-item, multi-level product-structure...

For the problem of lot-sizing on a tree with constant capacities, or stochastic lot-sizing with a scenario tree, we present various reformulations based on mixing sets. We also show how earlier results for uncapacitated problems involving (Q,SQ) inequalities can be simplified and extended. Finally some limited computational results are presented.

This paper introduces the single item lot sizing problem with inventory gains. This problem is a generalization of the classical single item capacitated lot sizing problem to one in which stock is not conserved. That is, the stock in inventory undergoes a transformation in each period that is independent of the period in which the item was produced. A 0 1 mixed integer programming formulation o...

This paper breaks new ground by modelling lot sizing and scheduling in a flexible flow line (FFL) simultaneously instead of separately. This problem, called the ‘General Lot sizing and Scheduling Problem in a Flexible Flow Line’ (GLSP-FFL), optimizes the lot sizing and scheduling of multiple products at multiple stages, each stage having multiple machines in parallel. The objective is to satisf...