Minimization Of Defect And Rejection Rate In Convertex (Finishing Section) Using Six Sigma DMAIC (Case Study Of Messebo PP Bag Production)

Six Sigma tools and techniques have been universally utilized and proved technique for quality and productivity improvement in the manufacturing sector.This case study applied Six Sigma;Define,Measure,Analysis,Improve,Control(DMAIC)and SQC tools,to investigate the most dominant defects,reduce the high rate of the defect,eliminate overall rejects as well as to increase Sigma level in the finishing section called convertex.If these things are performed exactly it is obvious that the overall quality and productivity of the company will improve.therefore,in the define phase,used tools such as SIPOC,(supply,input,process,output,customer)and questioner for the voice of customer(VOC).Then in the measuring phase also,the calculation of the existing data,the process capability plot has been done and the most six dominant defects in the section also identified using the Pareto diagram.Therefore,according to the results the sigma level was 3.17(Non-competitive),the defect rate 4.73 %,DPMO 47388.8 and the overall processing capability of produced quantity and defected units were 0.55 and 0.58 respectively then,after the vital few and trivial many are identified by Pareto diagram,the root cause of six most dominant defects are brainstormed through the Fishbone diagram in the analysis phase.The results and findings of the study showed after the corrective actions and recommended clues are suggested in the improvement phase,deliberately the overall quality and productivity of the section increased positively and the values are changed immediately.Therefore,after the improvement,the sigma level becomes 4.00(industry average),defect rate 0.61%,DPMO 6174 and the process capability of produced quantity and defect units becomes 1.19 and 1.26 respectively,which is very capable.At the last to sustain the results found in the improvement phase and to keep forward the changes the control phase was conducted and it has four procedures,namely Standardization,Documentation,Monitoring plan,and Response plan which are used to control the newly implemented changes and developed procedures.