Six Sigma Scrap Reduction in Water Bottle Manufacturing

Upon investigating the current state of the high scrap problem at Niagara Bottling's Phoenix manufacturing facility, it was found that 49% of the scrap was being generated at the bottling lines in the form of plastic bottles, and 39% of scrap took the form of preforms accumulated at either the bottling lines or the injection molding machines. The scope of this project includes all forms of polyethylene terephthalate (PET), but the large accumulation of scrap in these areas suggests a primary focus on the bottling lines and the injection molding machines. Further analysis of the bottling lines found that the filler at each line as well as the blower on line X1 were the biggest contributors to the scrap accumulation problem. Each of these machines was seeing over 0.4% of bottles rejected at the visual inspection units. Due to the underlying status and quality issues of the injection molding machines that were beyond the scope of this project, this process was only investigated for solutions involving the overall processes and people. Based on the data and process flow analysis there were several solutions proposed including a root-cause analysis of the highest faulting machines, the repair of the injection molding overhead conveyor systems, the creation of a low waste environment, and the implementation a scrap tracking and analysis process. Based on the current high variability in the scrap experience across all machines, it is recommended that Niagara Phoenix pursue the scrap tracking and analysis alternative. After the implementing the scrap tracking and analysis process, the initial results were encouraging and could potentially warrant the investment in a software platform that could automate the collection of data necessary for this process. Based on the initial results of the manual collection and analysis process, each individual line show signs of potential reduction in the scrap rate of over 50%. According to this improvement, purchasing the software platform would see a payoff period of only 36 days.