This paper explores the new approach to do STPC for PT. X during the period of 2023-2024, titled "Integrating New Sales Forecast with Production Plan in PT X," addresses the inefficiency in PT X's Short-Term Production Change (STPC). Traditionally, PT X's STPC process has been manually executed, consuming extensive time and being prone to errors, particularly during the critical weekly operational drumbeat. This study introduces a novel approach to enhance this process by integrating the latest sales forecasts with the previous week's production plans, utilizing previously underutilized software developed by a vendor. The research methodology encompassed observation, surveys, and trials, with a thorough analysis conducted using the DMAIC framework. The key finding is the validation and effectiveness of this integrated approach, which significantly reduced the STPC time by approximately 35%, thereby enhancing efficiency and reducing the propensity for human error. The implications for PT X are substantial, leading to faster responses to market changes and more streamlined supply chain operations. This research underscores the potential benefits of technological integration in traditional supply planning processes within the manufacturing industry.