Packing process is one of six main processes in flour process production. There is a problem in packing process, which a rate of output defect was exceeding the maximum tolerance that has been set by a company. The rate of output defect could affects quality and cost of the product. This study applies Lean-DMAIC method to solve the problem. The objective of this research is to decrease the rate of packing defect. The study begins with identifying packing process using Operation Process Chart and SIPOC diagram, and identifying customer's requirement using Critical to Quality tool. The problem is focused on sealing and filling subprocess. Moreover, this study also employ Failure Mode and Effect Analysis to analyze the potential causes of failure on sealing and filling subprocess and proposed several improvement. Result shows that the implemented improvements give several benefits for company, such as reducing 0,29% of defect rate in packing process, reducing 59% waste cost of material, and increasing 0,25s of sigma level.