PT LCI produces two types of precast: centrifugal concrete and non-centrifugal concrete. The company's main problem is a defective product in December 2021 with a defect percentage of 4.12%. In addition to defective products, in the production process of Jacking Pipe 450 mm, there is waste, namely activities that do not add value to the product, reducing product activity. This study aims to reduce waste and improve quality by applying Lean Six Sigma can be used with the Define, Measure, Analyze, Improve, and Control stages. Define stage in the form of diagrams Supplier-Input-Process-Output-Customer and Critical to Quality product. The Measure stage calculates Defects per Million Opportunities (DPMO), sigma level, Process Cycle Efficiency, and Value Stream Mapping mapping. The Measure results are calculated (DPMO) of 19867.54 units with a sigma level of 3.55 sigma, Process Cycle Efficiency (PCE) of 51.46%, Manufacturing Lead Time of 12.978 Hours, Exit Rate of 11.64 Units/Hour, and Process Velocity of 2.31 Activities/Hour. The waste is found in the form of defective products and waiting time. The tools used in the Analyze stage are Ishikawa diagrams and FMEA. This is used as the basis for proposed improvements at the improvement stage. The Control phase is the implementation of the proposed improvement activities in the form of cleaning the mold using mold oil, adding mold inspection activities with checklist tools, making machine work instructions and daily check sheet overhead cranes, and minimizing setup time. After the implementation, the DPMO value is 16666.67 units, equivalent to 3.62 sigma level, PCE value is 58.08%, Manufacturing Lead Time is 11.499 hours, Exit Rate is 3.48 Units/hour, and Process Velocity is 2.61 Activities/Hour.