Covid-19 outbreak has forced many manufacturing to create more effective and efficient business processes due to decreasing market demand and the economic slowdown. And total lead time process in a company's business processes is one of an indicator of the company's effectiveness and efficiency (Ridwan, Rifaitulloh, and Purba 2019). In this study, the Lean Six Sigma DMAIC approach has been successfully used as a tool to reduce process lead time in the overall internal supply chain. Before the application Lean Six Sigma DMAIC, total lead time process internal supply chain for 14 days 397 minutes, with a total value of NVA (non value added) or waste for 4 days 29.7 minutes. Based on statsitical analysis using ANOVA (analysis of variance) result, waste administration, transportation/motion, and waiting are the three primary wastes that cause a long lead time entire internal supply chain. It eliminates the NVA or waste in the internal supply chain process after applying a lean six sigma approach with  improvement process, such as: re-layout, re-design process, yamazumi chart, and job leveling.