carefully examined the outcomes of the JAD session that focused on defining the system structure of the WebStore. From this analysis, he identified six highlevel processes that would become the foundation of the level-0 DFD. These processes, listed in Table 6-4, were the “work” or “action” parts of the Web site; note that these processes correspond to the major processing items listed in the system structure.
Next, Jim determined that it would be most efficient if the WebStore system exchanged information with existing PVF systems rather than capturing and storing redundant information. This analysis concluded that the Web-
Store should exchange information with the Purchasing Fulfillment
System—a system for tracking orders (discussed in Chapter 3)—and the
Customer Tracking System (discussed in Chapter 4). These two existing systems will be “sources” (providers) and “sinks” (receivers) of information for the WebStore system. When a customer opens an account, his or her information will be passed from the WebStore system to the Customer Tracking
System. When an order is placed (or when a customer requests status information on a prior order), information will be stored in and retrieved from the Purchasing Fulfillment System.
Finally, Jim found that the system would need to access two additional data sources. First, in order to produce an online product catalog, the system would need to access the inventory database. Second, to store the items a customer wants to purchase in the WebStore’s shopping cart, a temporary database would need to be created. Once the transaction was completed, the shopping cart data could be deleted. With this information, Jim was then able to develop the level-0 DFD for the WebStore system, shown in Figure 6-18. He understood how information would flow through the WebStore, how a customer would interact with the system, and how