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The Closure Challenge Quality Improvement of Automotive Rear Door Closure Performance at Volvo Cars

Emma Wendelin ; Emma Remgård
Göteborg : Chalmers tekniska högskola, 2018. 126 s.
[Examensarbete på avancerad nivå]

This master thesis examines how to improve quality of automotive rear door closure performance by determining which factors critically affect closure performance, by using both qualitative and quantitative data. The research was conducted on the behalf of Volvo Cars to improve closure performance on automotive rear doors. However, the closure challenge is not limited by Volvo Cars only. The closure challenge, and how to achieve high quality closure performance, is examined by various car manufactures worldwide. Further, closure event is used as a term to describe the actual motion: when the rear door is set into motion to close. It is assumed that the door will result in total closure. However, the closure event can result in two different outcomes; either a successful closure event or an unsuccessful closure event. Hence, the closure event is evaluated by the term closure performance. Closure performance is measured by minimum closure speed (Y1) and minimum closure energy (Y2) required for total closure of the rear door: the door is secured into second lock mode. Furthermore, a comprehensive interview study was performed at Volvo Cars, where employees at several departments related to rear doors were interviewed. It was realized during the interview study that the closure performance is not limited by one department. Hence, a system perspective should be adopted when examine the closure performance. Continuing, the interview data provided the base for the determination of which type of factors to examine further. Based on the interview study, a number of mechanical factors related to the rear door were selected to be included in a Design of Experiment. The purpose of the Design of Experiment was to find which factors critically affected closure performance, and to support the research by quantitative data. A model which describes the relationship between the mechanical factors and closure performance was developed based on the Design of Experiment, which can be used to improve quality of the closure performance at Volvo Cars. The outcome of the closure event can be understood in advance by applying the model. Hence, the arrangement of the mechanical factors can be examined in advanced, in order to understand what the optimal arrangement of the factors are to achieve high quality closure performance. The model is suited for Volvo Cars, however, a similar model can be derived for other car manufacturer by utilizing the same method as described in the report. The Design of Experiment method are emphasized within the report to facilitate for externals to reuse the findings. Practical considerations or issues when performing Design of Experiment within an industrial context are also emphasized, since Design of Experiment is often underestimated as a method and not well distributed within Swedish corporations.

Nyckelord: variation, quality improvement, automotive rear door closure performance, Design of Experiment, D-optimal design, and split-plot design.

Publikationen registrerades 2018-06-20. Den ändrades senast 2018-06-20

CPL ID: 255163

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