REDUCING INFANT INCUBATOR PRODUCT REJECTIONS AT PT. XYZ THROUGH QUALITY IMPROVEMENT USING DMAIC METHODOLOGY: A CASE STUDY

Abstract

The rejection rate of infant incubator products at Company XYZ has shown a marked and consistent increase since 2021, peaking in 2024. Temperature instability is a type of failure with the highest Risk Priority Number (RPN = 360), contributing 72% of total rejections. This research aims to reduce the rejection rate through the implementation of the DMAIC (Define, Measure, Analyze, Improve, Control) methodology. The analysis was conducted using a Pareto Chart and Failure Mode and Effects Analysis (FMEA). The Improve phase included the replacement of temperature sensors with high-accuracy components (±0.1°C) and the addition of a 48-hour Performance Test in the final Quality Control process. These interventions addressed the root cause of temperature instability. As a result, the monthly rejection rate dropped from 5 units in September 2024 to zero rejections by January 2025, sustained through June 2025. Customer satisfaction validation through surveys showed an average score of 4.8 out of 5, with significant improvement in temperature stability and overall product reliability. This research proves that the DMAIC approach effectively reduces product defects, enhances product quality, and increases customer satisfaction in the medical device manufacturing sector.