Sensitivity Analysis of a Simulation Model for the Determination of the Utilization of a Production Environment with the LPBF-Process

Abstract

Additive Manufacturing is on the brink of industrialization. In addition to the technical aspect, the aspect of production planning and optimization is continuously gaining importance with the technology being introduced into production environments. In order to allow a production logistics positioning for a production environment equipped with Laser Powder Bed Fusion machines, a simulation model has been developed at the RWTH Aachen University Chair for Digital Additive Production DAP. By means of this simulation model, production logistics key performance indicators (KPIs) such as the utilization are calculated as a function of nine parameters describing the production environment. To demonstrate the validity of the simulation model and allow a better understanding of its behaviour, the influence of each input on the utilization is investigated. In this study, a Global Sensitivity Analysis (GSA) based on the Monte Carlo method is performed to quantify the importance of the parameters. For this purpose, a Variance Based Sensitivity Analysis (VBSA) is conducted, followed by a Regional Sensitivity Analysis (RSA), and a GSA based on the PAWN method, allowing to perform all three settings of GSA, namely Factor Prioritization, Factor Fixing, and Factor Mapping. Finally, the knowledge brought by the sensitivity analysis allows for a user-friendly simplification of the production environment model, thus permitting a prioritized increase of the utilization.