The biodrying process is a well-established method in solid waste management for reducing the moisture content of municipal solid waste (MSW), facilitating its mechanical treatment, enhancing energy recovery efficiency, and simplifying disposal. However, challenges such as variability in drying efficiency, seasonal fluctuations, and operational inconsistencies limit its optimization and broader applicability. This study undertakes a detailed evaluation of biodrying operations using Statistical Process Control (SPC) techniques to improve process stability and identify key factors influencing efficiency. Data collected over a one-year period from a waste management facility employing Herhoff Rotteboxes® reveal an average drying efficiency of 28%, with notable seasonal trends showing reduced efficiency during summer and fall. A regression model analyzing waste load, operational parameters, and seasonal effects accounted for 25% of the variability in drying efficiency, suggesting additional factors like waste composition and microbial activity significantly impact the process. This study highlights the value of SPC tools in monitoring process stability and demonstrates how targeted optimization strategies—such as seasonal adjustments and refined loading practices—can enhance biodrying outcomes. By addressing gaps in current practices, these findings contribute to the advancement of waste management technologies and support the development of more efficient and sustainable systems for handling municipal solid waste.