Application of PDCA and design of experiments to enhance palm kernel quality in ripple mill processing

The quality of palm kernel production is a critical factor influencing product marketability and profitability in the palm oil industry. This study applies the Plan–Do–Check–Act (PDCA) cycle and Design of Experiments (DOE) to improve palm kernel quality during ripple mill processing, with a focus on enhancing environmental sustainability. Kernel production quality data were analyzed using the Seven Quality Tools to determine the main sources of variation. A 22 factorial Design of Experiments (DOE) was conducted to evaluate the effects of sliding opening distance and rotor bar thread density on ripple mill productivity and efficiency. Analysis of Variance (ANOVA) results indicated that sliding opening distance had a statistically significant effect on output (P = 0.001), while the number of threads and interaction effects were not significant. Based on these findings, Standard Operating Procedures (SOPs) were developed to optimize ripple mill operation. Implementation of the SOPs over a 20-day trial reduced average moisture content, dirt content, and broken kernel percentage to 6.70%, 6.90%, and 14.74%, respectively, all meeting the established quality standards. The findings demonstrate that continuous improvement methodologies like PDCA, combined with DOE, can drive both operational excellence and environmental benefits in the palm oil industry.