Quality flow model in automotive paint shops

Improving paint quality is of significant importance for vehicle manufacturing. In this paper, a quality flow model is presented to analyse and improve quality in automotive paint shops. Specifically, we study the vehicle-painting process with multiple inspection stations. After each inspection, vehicles failed to achieve quality requirement will be repaired before moving to the next operation. In such systems, the quality variations may propagate along the painting process. To address this, a three-state quality flow model has been developed, and analytical formulas to evaluate product quality have been derived. In addition, to improve quality performance, a bottleneck analysis method has been introduced to identify the most critical stage that impedes product quality in the strongest manner. Two case studies at automotive paint shops are introduced to illustrate the applicability of the method.