Product quality and plant build complexity

Abstract

This paper assesses the hypothesis that plant build complexity impacts quality, suggests mechanisms to explain how complexity impacts quality, and offers countermeasures to mitigate this impact. We analyse automotive assembly data that supports the proposition that plant build complexity negatively impacts quality. In addition, this paper provides actual automotive assembly line work instructions and shows how they can be represented by the Gilbreths’ fundamental work elements and plant build complexity impacts these work elements. To highlight complexity's adverse impact on quality, we compare the actual work instructions at two automotive assembly line stations–one with very little complexity and one with extreme complexity. We list common automotive assembly quality lapses and describe how they can be caused or exacerbated by complexity. Finally the paper presents practical countermeasures to mitigate complexity's impact on quality. While based on the automotive industry, the lessons apply to all complex assembly lines.