Analysis of Misconstraining during Manual Assembly at Volvo Cars

Abstract

The rising need for increased robustness among products and processes worldwide has made it essential to research areas around geometrical variation and robust de sign. The presence of humans in the assembly process is inevitable due to the high levels of flexibility they can exhibit. However, the ways humans contribute to geo metrical variation in a robust design perspective have not been significantly studied. As an attempt to break this novelty barrier, this thesis focuses on investigating and examining the concept of misconstraining in the context of an error phenomenon at Volvo Car Corporation through a series of case studies, semi-structured interviews, and tests. Following a standard product development process, the main aim of the thesis is to provide proof of concept for misconstraining and develop a framework for analyzing misconstraining from a manual assembly perspective. The test cases present in the thesis have been designed by keeping in mind the parameters in volved in the manual assembly process, like assembly sequence and the surrounding conditions. The results have been corroborated by analyzing graphical plots and extensive evaluation of the various case studies. Ultimately, by utilizing all the information brought to light, the thesis resulted in developing a detailed mapping of the different causes and effects of misconstrain ing. Furthermore, the tests conducted revealed how the play between the guiding elements leads to geometrical variation in connection to human error contribution and how the change in screw sequence during assembly expedites misconstraining. The thesis concludes with a list of recommendations to tackle misconstraining and the envisioned forms of misconstraining. Also, a solid amount of information vital for future research has been presented with some exciting visualization about the concept moving forward.