Application Of Six Sigma In The Transmission Noise Improvement Of Company C

Six Sigma management originated in 1980 s.Along 30 years of development,it has become an effective method to solve the problems and improve the efficiency of enterprises.In particular,DMAIC(Define,Measure,Analyze,Improve,Controls)acts as specific tool to solve many annoying and complex quality problems.In this paper,the Six Sigma tooling DMAIC is used to solve the transmission noise problem which happened in Company C during new model pilot.In the Define stage,problem was defined and a tough target was set,zero defect in transmission noise inspection.In the Measuring stage,team used FMEA and other analysis tools,and found two keys factor,including deviation of gears pressure angle(FA)and diameter of transmission gear assemble hole.After verified measuring systems were good for these two factors with MSA method,the capability of processes were checked and found the data was bad.However,only after confirmed the relationship between those two factors did have relationship with the noise problem,further study were carried out.One is that testing for best machining according to DOE guide and finally find out proper diameter to make FA CP&CPK prefect.Other focus on the process and found out incline in the CNC machine and milling cutter for the case were wrongly used.As a result,best diameter of FA were used and recorded,while the incline problem and wrong cutter were corrected again.Both capability of two factors mentioned above were obviously improved and the noise problem were solve.What's more,SPC X-R sheet were used to monitor those two factor in case any change or risk happened.Through out of the six sigma improvement actions,noise problem solved and delivery went smoothly after that.Of course,money was saved.What is more important is,a team with six sigma improving sensing were set up and this,will surely make big contribution for a brand new age of six sigma development in Company C in the coming days.At the same time,the paper will be an example for reference when facing similar transmission noise problem.