APPLICATION OF A RELAX AND FIX HEURISTIC IN THE SOLUTION OF BATCH SIZING PROBLEM WITH LIMITED FRACTIONATION

This paper presents the application of a relax and fix heuristic to the lot sizing problem with parallel machines and limited splitting (LSPMLS). The problem is motivated by a real-world case in a white goods manufacturing company, whose production process is characterized by multiple items, multiple resources, multiple parallel lines, capacity constraints, and limited batch splitting. The mathematical model had previously been successfully applied to planning horizons of up to three months. However, instances with four-, five-, or six-month horizons remained unsolved within the four-hour time limit, highlighting the need for specific solution methods to tackle large-scale instances. In this work, we therefore developed a relax and fix heuristic, which proved effective in solving such instances.