Key Performance Indicators (KPIs) play a crucial role in systematically evaluating employee performance. This study integrates the Simple Additive Weighting (SAW) method with Design Science Research (DSR) to develop and validate a web-based KPI assessment system for IT Support staff. This system categorizes performance into three key areas: supervisor evaluation, routine tasks, and request-based tasks. SAW is chosen due to its effectiveness in multi-criteria decision-making and the objective ranking of employees. This research presents a scalable and practical solution for performance management through a structured web-based application. A simulation utilizing Bootstrap 5.1 incorporates real-time monitoring, ticket tracking, and KPI dashboards, enhancing data visualization and reporting. The results indicate that the proposed system enhances transparency, minimizes evaluation bias, and supports objective, data-driven decision-making. By integrating SAW within a structured decision support system, this approach fosters standardized performance assessments, ensuring fairer and more consistent employee evaluations. Future work should focus on real-world implementation and empirical validation.