Molding Material Reclamation: A Case Study of Manufacturing Process Analysis Using a Causal-Based Graphical Model Approach

Molding material reclamation in green sand foundries is a multi-stage process with a large number of variables that affect the resulting molding material quality and thereby the quality of the castings. We therefore investigate the applicability of causal graphical models to describe and analyse the reclamation process. These models provide an intuitive way to formalise causal relationships and to calculate the causal effects of interest while accounting for confounding influences. Using parts of Judea Pearl’s comprehensive theory of causal inference with graphical models, we analyse simulated and real-world data and compare the results with analyses that do not consider the underlying causal relationships. We show that causal models can help identify the true effects of interventions, while ignoring the causal structure can lead to biased results and incorrect conclusions.