Loss Reduction in a Water Cup Production Process : Drinking Water Production Plants’ Case Study

Abstract

This research aims to: (1) study and identify the causes affecting the production process that lead to waste in the drinking water production plant, (2) propose improvement guidelines to reduce waste in the production process, and (3) compare the results before and after implementing the improvement measures. The study employed a Design of Experiment (DOE) methodology. The population used in the study consisted of three types of drinking water products, which were the tank type, the bottled type, and the cup type. Samples were selected based on the product type that generated the highest amount of waste over the past three months. A total of 86,409 defective pieces were recorded, consisting of 28,601 units of bottled water waste, 57,790 units of cup water waste, and 18 units of tank-type water waste. Subsequently, data collection focused on the product category selected for experimental study. Research tools included a factorial design using Minitab software. Quality tools such as the fishbone diagram were applied to analyze and identify the factors contributing to waste generation. The findings revealed that the primary causes of waste were related to machine parameter settings, consisting of three key factors. DOE was then used to determine the optimal factor levels for machine parameter adjustment. After applying the optimal conditions, the waste rate was reduced from 30.48 percent to 13.97 percent, achieving a total waste reduction of 69.83 percent. The results confirm that DOE is an effective approach for identifying influential factors and improving production efficiency. The methodology can also be applied to waste reduction efforts in other manufacturing processes.