The research was carried out following the "Six Sigma" methodology; for this purpose, a detailed analysis of the lumber production process was made, including production from the forest to lumber storage. With the help of descriptive statistics, the causes that generated the problem of low yields and poor wood quality, performance parameters and process capacity were identified. For this purpose, tools such as: baseline, cause-effect analysis, Pareto diagram, time and motion study, quality and yield study and Six Sigma analysis were used. It was determined that the production process was defined by the following parameters: the standard production time was 783.5 minutes per production cycle, 34% of the sawn timber was affected by various defects, yields of 229.7 pt/m3 and a sigma level of 2.4. Based on the causes of the problem and analysis of the results, a combined improvement was implemented in the primary sawmilling process and in the storage area.