ABSTRACT In this paper, we introduce a case study of modeling, analysis, and continuous improvement of a door production line at an automotive body shop using production systems engineering methods. Analytical models have been developed, and recursive procedures have been derived to evaluate line production rate. An arrow-based bottleneck analysis method is introduced to identify the bottlenecks, whose improvement can lead to the largest improvement in system performance. Such methods provide a quantitative tool for plant engineers and managers to operate and improve door production line to achieve high productivity, and are also applicable to other large volume manufacturing systems