A production programming model multistage with intermediate stocks

Abstract

In this article is presented a mathematical model for production programming in two stages, the first one being composed by different machines that operate in a parallel way, and the second one, formed by a section for the items packaging. The objective of the model is to minimize production costs basing on the items arrangement, for both better machines choice, and for the correct production scheduling, since the time and the preparation cost of the machines for the manufacture of a new item is dependent on the sequence in which they are made. Due to the complexity of the mathematical model, where it isn't possible to obtain a great solution in an acceptable time for the industry standards, the model is solved with a method of relaxation of integer variables called relax-and-fix, where with it's obtained promising results.