Optimizing Pre-assembly Line Efficiency Using Lean Principles : A Case Study at Volvo CE

In today’s manufacturing landscape, the demand for increased flexibility, efficiency, and product variety is driving a shift toward more modular and adaptive production systems. To meet these challenges, companies are exploring ways to streamline operations. The goal is to eliminate inefficiencies without compromising quality. This study investigates how Lean Production principles can support that transformation through a case study at Volvo Construction Equipment. The focus is on a newly implemented pre-assembly line and applies a deductive methodology combining interviews, 3M observations, Spaghetti Diagram, and time studies. The results highlight recurring sources of waste, including motion, ergonomic strain, and workload imbalances. Based on the findings, improvement proposals are presented: merging three stations into two to balance workload, repositioning material façades to reduce motion waste, and introducing standardized quality checks between stations. These suggestions are grounded in Lean principles such as Heijunka, Jidoka, and 5S, and aim to enhance both efficiency and quality assurance. The study contributes practical insight into how Lean tools can be adapted to complex, low-volume, and high-variation production environments. It also highlights the importance of integrating operator feedback and ergonomic considerations into continuous improvement efforts.