A simulation–optimization approach for a cyclic production scheme in a tablets packaging process

Abstract

This paper discusses an iterative simulation–optimization approach to estimate high-quality solutions for the capacitated lot-sizing problem with linked lot sizes and backorders (CLSP-L-B) based on probabilistic demands. An uncertainty framework for incorporating the impact of simulated demand scenarios is embedded into the CLSP-L-B. The framework is generalized by a variable neighborhood search (VNS) approach, which accelerates the search for stable and cyclic production schemes. Moreover, an exact mathematical problem formulation is introduced for the generalized model framework. Anonymized real-world data of four tablets packaging robots is used for evaluation. The experimental design covers nine classes of demand uncertainty per packaging robot. Additionally, proposed solutions are evaluated against an established benchmark approach from literature for each uncertainty class in terms of manufacturing costs and customer service levels. Finally, planning rules and managerial insights are given for the packaging robots.