Metalsa is a commercial truck frame rail manufacturer that runs a highly automated facility where each rail is custom made. The high degree of customization leads to a large amount of throughput variation decreasing the production stability plantwide. Simulation software modeled part of Metalsa’s automated line to test various improved rail sequencing methods. The results of the simulation testing, found a method of rail sequencing that creates the greatest stability. By resequencing the order of rails, production variability decreased and Metalsa’s throughput is expected to increase along with the operating availability. By implementing this critical process, the plant production is expected to run much closer to its full capacity.