During February 2025, KShiMin enhanced the Hospital_Management_System repository by developing a feature that integrated service items into the invoicing process. Using Java and object-oriented programming principles, KShiMin linked the Service class to invoices and implemented a method to calculate total amounts based on included services. This update improved financial accuracy by ensuring invoice totals reflected all billable services, streamlining customer invoicing workflows and reducing manual reconciliation. The work also involved modularizing service-related calculations and updating data models for better maintainability. While the contribution focused on a single feature, it demonstrated solid software design and effective application of Java development skills.