Pharmacy Management System use case diagram models three distinct user roles—Administrator, Pharmacist, and Cashier—each with specific functional responsibilities. The Administrator manages inventory (add, update, delete medicines), suppliers, and generates comprehensive reports; the Pharmacist handles medicine searches, expiry monitoring, and return processing; the Cashier executes point-of-sale transactions including invoicing, discounts, and payment selection. All roles authenticate via Login to System with Role-Based Access Control, ensuring secure separation of duties and audit trails. This diagram demonstrates best-practice role-based access patterns for healthcare retail, helping teams design scalable, compliant pharmacy software that separates clinical, administrative, and transactional concerns. Fork and customize this diagram on Diagrams.so to match your pharmacy's specific workflows, add additional roles, or integrate with external systems like inventory APIs or payment gateways.