Applying Six Sigma to Quality Improvement in Construction

Abstract

Taiwan is in a seismically active zone because it is located in the earthquake-prone Pacific ring of fire. The cracks in lightweight partition walls caused by frequent earthquakes decrease customer satisfaction and increase repair costs in the case company. This research demonstrates how a Six Sigma team can determine and improve the key input variables affecting the cracks in lightweight partition walls. A case study methodology is used in this research to illustrate the tools of Six Sigma by using the project charter to define problems, by using tools of process mapping to display all the input and output variables affecting cracks in lightweight partition walls, by using the C&E (cause-and-effect) Matrix to select highly correlated input variables, and by using failure modes and effects analysis (FMEA) to identify causes of the cracks. Unlike conventional Six Sigma, finite-element analysis (FEA) simulation software ABAQUS was used instead of statistical tools to verify variables and to identify initial causes of cracks because data collecting was time consuming. The results showed that a 1-cm preset spacing between the board and the main structure substantially reduces cracks caused by earthquakes. A new earthquake-proof construction method has been developed based on the finding of this research and was recently granted a new patent (M 431196) by the Intelligent Property Office in Taiwan.