THE PROPOSED IMPROVEMENT OF PREFORM QUALITY AT PACKAGING SERVICE DIVISION PT X USING SIX SIGMA METHODOLOGY

• Main Author: Kurnia Ramadhan, Farhan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/47086
• Institution: Institut Teknologi Bandung

PT X is a company producing non-alcohol soft drinks.. PT X also produces their own PET bottle. The raw material for producing PET bottle is called preform. Preform is made by Packaging Service Division (PSD). Nowadays, PSD is considered to be operating at a great conversion cost. Quality cost (internal and external failure cost) accounted for 40% of the total production cost that could be reduced. From January to July 2019, rate of defective preforms is around 0,37 – 0,54%. It doesn’t meet the company’s target, 0,1%. The cause of defective preforms needs to be known so improvements that will reduce them can be proposed. Efforts to reduce the proportion of preform defects are carried out with the Six Sigma Methodology which consists of five stages of DMAIC, namely Define - Measure - Analyze - Improve - Control. The results of the define stage are the formulation of the Six Sigma Project with project charters, as well as observing the existing conditions of the research object. In the measure phase, it was concluded that the preform production process with injection molding is still not stable and has a process capability that can still be improved, namely at the sigma level of 3.26. In the analyze phase, the type of defect to be searched for is determined, namely damage to the gate. The results of the analyze stage is the causes of defects by the Delphi method which is illustrated in the fault tree analysis (FTA) and estimated the percentage of occurrence of each factor. The root causes of the problems that contribute greatly to the emergence of defect factors are unstable cooling systems, insufficient air supply, and predictive maintenance. In the improve phase, it is proposed to solve each root of the problem and evaluate its economic viability. Proposed improvements related to the cooling system are implemented while other proposals are still being considered. In the control phase, after repairs were made, the proportion of preform defects was reduced to 0.31%. Thus, it is expected that the cost of quality wastage will decrease and PSD can increase its competitiveness.