Point-of-sale cash register system modeled as a use case diagram with three actors: Cashier, Manager, and Customer. The Cashier performs core operations including scanning products, registering sales, processing payments, and viewing cash balance, while the Manager supervises operations and closes the register at shift end. The system enforces a workflow where payment processing depends on sales registration, and shift closure includes preparing change for the next cashier. This UML use case model demonstrates role-based access control and sequential business processes essential for retail operations. Fork this diagram on Diagrams.so to customize actor roles, add payment methods, or extend it for multi-register environments.