Computer repair service businesses that still rely on manual, chronologically ordered queues commonly experience a structural inefficiency: short, simple jobs are delayed behind longer and more complex repairs, which inflates average customer waiting time and removes any real-time visibility into repair status. This problem mirrors a well-documented limitation of First Come First Served (FCFS) scheduling in computing systems, where job ordering by arrival time rather than job characteristics produces suboptimal queue performance. This study addressed that gap by designing and implementing a web-based Service and Repair Management Information System that embeds the Shortest Job First (SJF) algorithm, strengthened with an aging mechanism to prevent the starvation of long-duration jobs. The system was developed using the Waterfall model, built on the Laravel 10 framework with a MySQL database, and structured around four role-based modules: Admin, Technician, Director, and Customer. The scheduling logic applied the priority formula Priority = Duration ? (Waiting Time × 0.5), which dynamically lowers a job's priority value the longer it waits, gradually moving long-duration jobs toward the front of the queue without abandoning the core SJF principle of minimizing average waiting time. Black Box Testing confirmed that all ten primary system functions, including the SJF queue calculation, the aging mechanism, real-time status updates, and the public tracking portal, operated correctly and met the defined functional requirements. The findings indicate that the integration of an algorithmic scheduling mechanism into a web-based service management platform is both technically feasible and operationally effective for small computer repair businesses, extending the application of SJF scheduling beyond its traditional CPU-scheduling domain into commercial service queue management.