BizTalk Server Goal: Transcend Semantic Boundaries

BizTalk Server Goal: Transcend Semantic Boundaries While the BizTalk Framework links applications or businesses with each other, it doesn't do so directly. Instead, it provides an additional layer of functionality that is responsible for data transformations. A simple scenario is shown in Figure 1.7. The purchasing application in Business A needs to send an order document to a purchase processing application in Business B. Unfortunately, the applications are incompatible. Therefore, if the two businesses attempted to communicate directly, each application would not be able to interpret the other's data. The meaning of the data is clear only within each application. We can say that there is a semantic boundary around each application-outside of the boundary, the meaning of the data cannot be interpreted. The incoming data can't cross the semantic boundary either. Direct communication is therefore impossible. Figure 1.7 A business process using the BizTalk Framework BizTalk Server provides an extra layer that transcends the semantic boundary. In other words, BizTalk server A creates a mapping between the document in the original form and the XML format that it can easily interpret. The document is then sent over the Internet, in XML format, to BizTalk server B. This server in turn provides another mapping, this time between the XML document it just received and the form that represents the semantics understood by Application B. A Practical Example of Business Processing Let's see now how useful transcending the semantic boundaries is. To understand how BizTalk Server overcomes the semantic boundaries between applications and businesses, let's look at a specific example. Imagine you are a customer who wants to buy a computer by using a seller's Web site. You fill out the form specifying your order, type in your credit card number, and click the Order Now button. What happens next? The details are shown in Figure 1.8. Figure 1.8 An example of business processing Your order crosses the first semantic boundary and is received by the Order Management application on the seller's Order Management server. The application immediately sends out the order acknowledgement (across the same semantic boundary), so that you know your order was received correctly. To make sure you are able to pay for the computer you are buying, the Order Management application checks your available credit. Most likely this will involve accessing the financial database on another computer (the Finance server) in the finance department and crossing yet another semantic boundary. This server receives the request for the credit check, verifies that you are in good standing, and returns the confirmation to the Order Management application on the Order computer. Again, another semantic boundary is crossed. Next, the Order Management application needs to arrange for your order to be fulfilled. Toward this end, it sends a request to the Warehousing application, on the Warehousing server, crossing a semantic boundary for the fifth time. The Warehousing server consults the Warehousing database to verify that the computer system you ordered is available and can be shipped to you. It then sends the message back to the Order Management application, across the same semantic boundary. The Order Management application then contacts the Shipping application on the Shipping server to arrange for shipment, which involves yet another boundary. The Shipping application then arranges for the goods to be shipped to you. At the same time, it sends the shipping confirmation across the semantic boundary to the Order Management application on the Order server. This confirmation also contains information about the estimated delivery time for your computer. Of course, you want to know when you can expect your computer to arrive at your doorstep, so the Order Management application sends that information to you across the semantic boundary. After ordering the goods, it is time to arrange to pay for it, so the Order Management application sends the total charge to the Financial application on the Finance server, across another semantic boundary. As described, this process involves at least five different-possibly incompatible-systems and crossing many semantic boundaries. Without BizTalk Server, it would be difficult to perform the business transactions described in this example. Lesson Summary Business integration is a challenge facing many businesses. The two primary issues in integration are the need for cross-platform integration and business-to-business scalability. Older solutions to these problems were resource-consuming, expensive, and did not necessarily perform well. Specifically, they didn't provide a platform for electronic data exchange that would make the business accessible from anywhere at any time, reduce process time, help the consumers make better decisions faster, manage and share knowledge effectively, or manage dynamic business relationships efficiently. BizTalk Framework 2.0 is a business framework that addresses both these integration problems efficiently because it is based on XML and is therefore completely platform-independent. The central idea for this framework is XML-based message transmission. BizTalk Server 2000 is Microsoft's implementation of the BizTalk Framework. BizTalk Server also supports EDI, and there are plans for it to soon support RosettaNet.