PT. XYZ is a manufacturing company that produces concrete. One type of product produced is precast concrete with a make-to-stock production system. During this production process the company experienced problems such as product defects. There is a final product that does not meet the specifications that have been set. The purpose of this study is to identify the most dominant level of damage, analyze the factors causing the damage, and provide suggestions for improvement to improve product quality. This study uses the DMAIC (Define, Measure, Analyze, Improve, and Control) method and the FMEA (Failure Mode Effect Analysis) method. Based on the identification results, the most dominant defect is void defects, which are 60 units out of a total of 162 defects. FMEA results show that the largest component with an RPN value of 280 is caused by human factors. Recommendations for suggested improvement to the company is to apply the maximum workload calculation to reduce operator fatigue.