PT KAEF is one of the pharmaceutical manufacturing industries in Indonesia that produces various kinds of drug variants. Currently, PT KAEF is experiencing problems in the form of product defects that exceed the company's standard, which is 1%. By using the DMAIC Six Sigma Statistical tool (Define, Measure, Analyze, Improve, and Control), it is possible to evaluate the possibility of failure of the production system so that the cause of each product defect can be identified and get the right problem-solving solution and with Failure Mode Effects Mode can be known the solutions for the priority problems. From the search results, it can be seen that liquid products are the products with the most defects, with the causes of defects caused by errors in work procedures and the use of old machines. From the improvement results, it was found that the level of product defects decreased from 2, 26% to 0, 93% or in sigma level increase from 4, 18 to 4, 46.