<![CDATA[Production downtime poses a critical challenge in automotive manufacturing, exerting a direct influence on operational efficiency, line productivity, and corporate profitability. The present study was conducted at an Indonesian automotive company whose shutter production line recorded a downtime level of 15 hours per month (15%)—markedly exceeding the industry benchmark of 5 hours per month (5%). The objective was to systematically diagnose the root causes of this downtime and to design a measurable engineering intervention. The methodology combined a Fishbone (Ishikawa) Diagram structured around the 5M+1E framework—Man, Machine, Material, Method, Measurement, and Environment—with a Pareto analysis applied to six months of historical downtime records. The analysis revealed that the inefficient manual shutter-replacement procedure was the dominant contributor, accounting for 42% of total downtime. In response, a trolley shutter system—a mobile steel cart fitted with an adjustable lifting arm—was engineered and rolled out across four phases: prototyping, operator training, piloting, and full deployment. A six-month post-implementation evaluation demonstrated a statistically significant reduction in mean monthly downtime, falling from 15.0 ± 2.3 hours to 5.0 ± 1.1 hours, a 66.7% decrease (t(5) = 9.84; p < 0.001). The per-event shutter-replacement time likewise dropped from 47 minutes to 14 minutes. These findings confirm that pairing systematic root-cause analysis with a well-targeted engineering intervention constitutes an effective and quantifiable strategy for curbing production downtime in automotive manufacturing settings.]]>
