A vehicle’s exterior fit and finish, in general, is the first part to attract customers. For this reason, customers consider the J.D. Power report which classifies all vehicles based on different criteria. One of the criteria is the vehicle exterior fit and finish which is measured by two important factors called Flush and Gap. Automotive exterior engineers have been motivated in the past few years to increase their focus on optimizing the vehicle’s exterior panels split lines quality and minimizing variation in fit and finish to address customer and market quality standards.
Design engineers focus on controlling the deviation from nominal build objective and minimizing it. This study focuses on addressing the contributed factors that impact the quality of fit and finish. These critical factors resulted from the design process, product process and from the assembly process. An empirical analysis was used to minimize the fit and finish deviation.
Models that accurately describe the response values by experiments helped identify the most critical factors, and an analytical model and Response Surface Methodology (RSM) were used to optimize the acceptable values on these factors. Early results showed that some of these factors are critical for improving the quality of the fascia cutline fit and finish by obtaining more consistent gap and flush along the rear fascia cutline as well as reducing the offset issue.
The results of this study identified 17 critical factors which were split between controls and can be dialed to change the magnitude of the results and noises which have less effect on changing the results. Also, the 17 factors were separated into factors that affect Gap “α” or factors that affect flush “β” or both. Eight factors were selected based on production experience and based on their levels. Empirical analysis was conducted to generate regression models for both α & β. The selected factors were tested for their effect; also, the study took in consideration of different combined effect of these factors. Optimization with these factors were conducted for α & β. The results show that α can approach ±0.5 mm and β can approach ± 1 mm. The conclusion is that the consistency of α & β along the fascia to bodyside panel cutline (defined as ϴ) will be maximum when both α & β are minimum. The ultimate goal is to reach the stretched target which means zero mm gap and zero mm flush.
The role played by interdependences in ERP implementations: An empirical analysis of critical factors that minimize elapsed time