A REVIEW OF TACTICAL PLANNING MODELS

The aim of this paper is to give an overview on models and methods used to solve tactical planning problems.The modeling and the elaboration of the well-know tactical planning problems(master planning & scheduling,material requirement planning and multi-site planning)are discussed.These problems are modeled from two"lot sizing"models called the Capacitated Lot Sizing Problem(CLSP) and Multi Level Capacitated Lot Sizing Problem(MLCLSP).From both models,a lot of extensions has been proposed in the literature.The purpose of this paper is twofold:first,classifications of the CLSP and MLCLSP as well as their extensions are given.For each model,the major scientific contributions are mentioned.These classifications made from seventy papers give an overview of"lot sizing"models dedicated to the MPS,MRP and Multi-site and show the diversity of models.Second, from a classification,an analysis of methods used for each model is given.The instance size,best gap and reference for gap computation are given for each contribution.This work can be used to elaborate an optimization tool for tactical planning problematic such as Advanced Planning System.