Using .NET to Build a Distributed Web Application
Internet technology has been changing people's lifestyles and business practice models. Now, the Internet itself is experiencing a paradigm shift. It is quickly evolving from Web sites that deliver simple user interface pages to a next generation of programmable Web-based applications.
In previous chapters, we discussed major features of the .NET technology, including ASP.NET, ADO.NET, and Web Services. Not only do these features make development of Web-based applications much easier and simpler, they also allow for more powerful, distributed information-processing systems to be built based on the Internet. In such a system, ADO.NET interfaces the data sources, ASP.NET facilitates browser-based information presentation, and Web Services deliver functional services over the Web. Furthermore, existing applications may also be integrated in this framework.
In the case study presented in this chapter, we build a Web-based distributed application for a group of travel agencies that have formed a loosely coupled consortium called Travel Agency Union, or TAU, in order to share their business opportunities. Information systems of the participant agencies are extended using .NET technology, creating an integrated system over which information can be exchanged. We call this integrated system TAU.NET. TAU.NET unites the participant agencies to form a large entity that can help agencies better serve their customers.
11.1 The TAU Business Model
Each TAU member is a travel agency that runs its business independently, providing its customers with products and services, such as flight reservations, hotel reservations, rental car reservations, and group tours and cruises. Each agency processes its business transactions using the following functions.
Inquiry. Allows the agency and/or its customers to retrieve products and services information
Reservations. Allows the agency and/or its customers to reserve and manipulate the transaction with desired products and services
Bill/Payment. Bills the customers and acquires the payment from the customers as well as receives the invoices and makes the payment to the vendors
By joining TAU, member agencies can expand their functionality into the distributed environment of the Internet. The enhanced functions include
Inquiry. A member agency may allow other member agencies to retrieve its products and services. In addition, a customer may retrieve the products and services via a single entry point, the Web site of his or her own agency.
Reservations. Via the Web site of a single agency, a customer may manipulate his or her transaction with products and services of multiple TAU agencies, including reserve products and/or services, as well as update and cancel reservations.
Bill/Payment. For a transaction involving multiple TAU agencies, the agency that directly interacts with the customer calculates the total cost and bills the customer. Other agencies that are involved in this transaction maintain their own accounts receivable information for the products and services they provide.
TAU.NET is a business network that provides users with a single entry point to accessing all the resources shared by its members. The business concept of TAU.NET is shown in Figure 11-1.
Figure 11-1 Basic business concept of TAU.NET.