Optimization of Cyklop Ink Usage in the UHT Box Coding Process Using the DMAIC Approach: A Case Study at PT Indolakto Factory Cicurug 3

Abstract

The use of factory supplies is one of the areas that requires control to improve production cost efficiency. This case study examines the optimization of Cyklop ink usage in the UHT box coding process at PT Indolakto Factory Cicurug 3 using the Define–Measure–Analyze–Improve–Control (DMAIC) approach. The initial condition showed an average usage ratio of 17.689 ctn/cartridge during January–December 2024. Pareto analysis identified Cyklop ink as one of the major contributors to factory supplies costs. Stratification by production line showed relatively consistent ratios for Lines A, B, and C, at 17.663, 17.665, and 17.737 ctn/cartridge, respectively. Observations of production output across several periods also indicated that changes in production volume were not accompanied by meaningful changes in the usage ratio. Root cause analysis using the 5 Whys identified three primary causes: the printer could not detect the actual amount of ink remaining in the cartridge, the LED alarm indicator was too small, and no detection system was available to identify instances in which the production code was not printed. Improvements were subsequently implemented through the reuse of residual ink by modifying the cartridge, installation of an external visual alarm, and addition of a camera-based detection system. The average ratio during January–June 2025 increased to 28.719 ctn/cartridge, representing a 62.36% improvement over the baseline and exceeding the target of 22.969 ctn/cartridge. During the monitoring period from July–September 2025, the average ratio reached 29.901 ctn/cartridge. Financial validation recorded actual cost savings of IDR 392,672,035 per year, with an investment of IDR 1,084,080 and an ROI of 1,812%. These results demonstrate that DMAIC can systematically integrate baseline condition analysis, root cause verification, technical improvement actions, and performance control.