The vending machine system data flow diagram (DFD) illustrates the data exchanges among customers, owner, database, suppliers, and payment gateway. The customer selection of items followed by payment actions leads to updated stock records in the database. The owner tracks inventory levels and adds new products to the machine while using third-party suppliers to request restocking. The cloud server maintains inventory data synchronization which provides continuous up-to-date information. The payment gateway ensures secure transaction processing which leads to payment confirmation before item dispensing. This DFD suits businesses that have started using smart vending technology.