Flow simulation of Body In White : Optimization of the production sequence and identification of bottlenecks at Volvo Trucks plant in Umeå
Abstract: In this study, a discrete event model was created and used in combination with an optimization method to find the optimal production sequence at Volvo Group’s cab plant in Umeå. The optimization was performed with a heuristic approach combined with a genetic search algorithm. The result provides an optimized production sequence with an increased production performance. Potential improvements in the production flow were identified to significantly increase the throughput. Volvo Group Trucks Operations plant in Umeå is a part of Volvo Group AB and is one of the world’s largest manufacturers of heavy duty trucks. The plant in Umeå produces cab bodies and consists of Stamping and Part production, Body In White and the Paint Shop. As of today, the plant produces about XXX produced cabs per week with the goal to achieve the invested capacity of 1666 produced cabs per week. The production is structured with a daily scheduling of the cab production. Today cabs are produced in the same sequence as the orders are received. There has been an investigation regarding the production capacity in the past but further investigation was required due to insufficient data available at the time. Volvo wants to investigate the potential improvements in the BIW unit, increase the production rate and reach the level of invested capacity. Therefore, this project was introduced which led to the following problem definition: “What is the optimal production sequence in the BIW unit?” To further find potential improvements, a secondary problem definition got formulated: “How would the production sequence be affected if the current biggest bottleneck were removed?” The objective was achieved with Discrete Event Simulation, where heuristic based sequences were optimized in a genetic search algorithm. This resulted in identified sequence patterns, which were used to improve the production sequence. When analyzing the model, the floor subflow was identified as the biggest bottleneck in the production. A general suggestion would be to avoid large batches due to significant risk of limiting the throughput. Results suggest that sequences should be in cycles of 3FH-1FM with segments of batches as long as the floor buffer does not run out of parts. This resulted in a potential increased throughput of 3.2-3.7% for the Body In White. If the biggest bottleneck were to be removed, there would be a potential production increase by roughly 10% compared to the production today.
AT THIS PAGE YOU CAN DOWNLOAD THE WHOLE ESSAY. (follow the link to the next page)