This paper presents a comparative study of production planning in the automotive industry, contrasting fixed industrial capacity constraints with real-time data utilization. It employs real data from a Renault Group manufacturing facility to demonstrate the benefits of improved component availability visibility. We introduce the comparative study on a use case. This work emphasises how real-time data can improve the supply chain’s performance and the production plan’s quality. By incorporating real-time data, the study successfully reduces the average lead time for order manufacturing and minimizes average lateness by 0.5 production days. The study contributes insights into the impact of constraint flexibility, particularly regarding component availability, on real-world production planning outcomes.