In this exercise, you will “explode” an event handling process into a level 1 DFD. The exercise focuses on the process used to complete a purchase at the “self-checkout lane” at a retail store. The basic process should be familiar to you. To simplify the scenario, we assume that only credit/debit card payments are allowed in this lane (no cash, checks, or food stamps). We start with a DFD fragment that has been created for this situation. This fragment shows one event-handling process and the data flows it receives and sends to external entities and data stores. This fragment was extracted from the Level 0 diagram to help us focus just on this event.

The event handling process includes four subprocesses:1. Process purchase items 2. Update inventory on hand 3. Process payment 4. Record sales transaction details

Draw the level 1 diagram for Process 1. Use the suggested sub-processes listed above as the process components of the level 1 diagram. Remember that all data flows and data stores on the parent diagram must also appear on the child diagram, but you will likely add more data flows on the child diagram.

Customer Item UPC Amount Due Payment- Receipt D3 Sales Transactions CC Payment CCCH Response 1 Check Out Process Final -Transaction Details Credit Card Clearing House Item UPC Item Details Items Purchased Debit Payment ACH Response D1 Items D2 Inventory On Hand Automated Clearing House