This thesis outlines the application of the six sigma methodology to improve the fit of an automotive closure panel. Six sigma is a quality improvement methodology currently used by many successful companies to address their top customer issues. The methodology follows 5 phases - Define, Measure, Analyse, Improve and Control - and, in the context of this work, is applied in a manufacturing plant to improve the fit of a trunk lid on a luxury saloon car. Poorly fitted automotive closure panels adversely affect road noise sealing and also deteriorate the vehicles' styling and aesthetic quality. Hence, correctly fitted panels are a key factor in achieving customer satisfaction.

The application of the methodology led to the identification and improvement of several root causes including the for-aft position of the hinges, the body side profiles and the tooling strategy for supporting the panel while the structural adhesives are cured.

The case study emphasizes the importance of effective measurement systems and gauge R&R techniques and statistical tools such as t-tests which were used extensively. Cause and effect diagrams were also used and their positive impact on team development is discussed. The six sigma methodology was critically assessed with particular reference to the importance of a comprehensive problem definition and scope.