Defect Reduction of Door Mirror Adjustment

Abstract

The objective of this thesis is to study about defect reduction of door mirror adjustment for door mirrorfactory. Production process is receiving parts from supplier and production by ourselves. After that, parts willbring to assemble to finish goods. Then we deliver them to customer.The data collection of before improvement was conducted 1 year that was from January X December 2008.This data was inhouse defect and customer claim from quality control department. There were total inhousedefect 5,033 pieces that was total average repair cost 229,821 baht. These were A model 4,686 pieces whichwas average repair cost 213,213 baht and total customer claim 4,154 pieces which was total average repaircost 4,136,140 baht. These were A model 4,000 pieces which was average repair cost 3,982,000 baht.This model incurred the largest total average cost that was calculated to 90.09%From raw data, researcher chose model and problem that was the most effect to company. After that,analysis for finding root cause of occurrence and outflow including project of improvement by using QC7 Tools and Six Sigma including, project of improvement and prevention as follow :1) Purchasing new injection machine2) Making new mold3) Issue Xbar X R Chart, Inspection Data Sheet and equipment and machine check sheetdocumentsAfter implementation of improvement project, the defect data was collected for 3 months fromOctober X December 2009. The total defect was reduced to 7,298 pieces that was total average repair cost3,504,588 baht or about 83.54% that we expect to achieve the target at 4 ppm.