Apply – Systems Requirements Presentation / Fundamentals Of Business Systems Development

Process modeling for an Internet-based electronic commerce application is no different than the process followed for other applications. In Chapter 6, you read how Pine Valley Furniture (PVF) determined the system requirements for their WebStore project, a project to sell furniture products over the Internet. In this section, we analyze the WebStore’s high-level system structure and develop a level-0 DFD for those requirements.

PINE VALLEY FURNITURE

Process Modeling for Pine Valley Furniture’s WebStore

After completing the Joint Application Design (JAD) session, senior systems analyst Jim Woo went to work on translating the WebStore system structure into a DFD. His first step was to identify the level-0—major system—processes. To begin, he carefully examined the outcomes of the JAD session that focused on defining the system structure of the WebStore system. From this analysis, he identified six high-level processes that would become the foundation of the level-0 DFD. These processes, listed in Table 7-4, were the “work” or “action” parts of the Web site. Note that each of these processes corresponds to the major processing items listed in the system structure.

Table 7-4 System Structure of the WebStore and Corresponding Level-0 Processes

WebStore System

Processes

Main Page

Product Line (Catalog)

Desks

Chairs

Tables

File Cabinets

Information Display (minor/no processes)

1.0 Browse Catalog

2.0 Select Item for Purchase

Shopping Cart

Checkout

Account Profile

Order Status/History

Customer Comments

3.0 Display Shopping Cart

4.0 Check Out Process Order

5.0 Add/Modify Account Profile

6.0 Order Status Request

Information Display (minor/no processes)

Company Information

Feedback

Contact Information

Next, Jim determined that it would be most efficient if the WebStore system exchanged information with existing PVF systems rather than capture and store redundant information. This analysis concluded that the WebStore should exchange information with the Purchasing Fulfillment System (a system for tracking orders [see Chapter 3]) and the Customer Tracking System (a system for managing customer information). 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, information will be stored in the Purchasing Fulfillment System. When a customer requests status information on a prior order, information will be retrieved from the Purchase 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 wanted to purchase in the WebStore’s shopping cart, a temporary database would need to be created. Once a transaction is completed, the shopping cart data can be deleted. With this information, Jim was able to develop the level-0 DFD for the WebStore system, which is shown in Figure 7-22. He then felt that he had a good understanding of how information would flow through the WebStore, of how a customer would interact with the system, and of how the WebStore would share information with existing PVF systems. Each of these high-level processes would eventually need to be further decomposed before system design could proceed. Yet, before doing that, he wanted to get a clear picture of exactly what data were needed throughout the entire system. We will discover the outcomes of this analysis activity—conceptual data modeling—in Chapter 8.