What is SAP XI ?

SAP Exchange Infrastructure (SAP XI) is one of the most powerful and widely used parts of SAP NetWeaver. At first glance, it seems pretty simple: SAP XI allows one application to send data to another application.

However, actually doing this job the right way is much harder that just sending a message from one place to another and back again. To solve this problem in a way that makes life easier for developers and provides all of the functions that applications need, SAP has added all sorts of powerful toolkits inside SAP XI.

In a way, SAP XI is a toolkit’s toolkit and is also essential to helping SAP NetWeaver fulfill its potential.

So how does this magical exchange of data happen? Start with the message itself. In SAP XI, the message is usually in XML (eXtensible Markup Language), a flexible format for storing data that can handle almost any kind of structure in a simple way.

SAP XI:

• Has a way to define XML messages.

• Stores the descriptions of messages in a repository and keeps track of where they should be sent in a directory.

• Has the ability to map the fields of one message to another. SAP XI can then route the messages from one place to another or to many others.

• Contains a special toolkit for building adapters that allows any program to send and receive messages.

SAP XI has a powerful toolkit for Business Process Management (BPM), which allows messages to become part of complex processes. This can help many applications communicate with each other the way that they have to when one business integrates its systems with another.

SAP XI acts like a superhighway: Whenever an application needs to send or receive a message, SAP XI is the road that carries it. SAP XI has on-ramps and off-ramps, and rules that make sure every message is received and read correctly when it reaches its destination.

In this translation of information, what you want is the complex logic of managing the conversation to be in the middle, in some sort of integration hub that transfers messages back and forth. SAP XI is that middle hub that’s designed to manage the complexity of the conversations.

Without XI

With XI

The classic example of reducing integration costs is by using a hub, rather than tying together application systems in a spider web fashion. SAP XI replaces many point-to-point connections with a single connection for each application to such an integration hub. Then if you change something in the landscape, you don’t affect the connection from the application to the hub. Each system retains its independence, whatever happens in the rest of the system landscape, because each system relies on the hub — the integration broker — to take the message to the appropriate application. Thus, you maintain one interface, and your customer order is good to go.

A common use of the central hub’s features is when SAP XI replaces a “fire and forget” purchase order with a monitored interaction. Say you need to send a business partner a purchase order, but because that’s a “fire and forget” kind of communication, it’s as if you’re sending an e-mail — you may know the partner will get the e-mail, but you don’t know when he’ll read it or respond to it.

But with SAP XI, you can use the BPM tool to control timing. You can send a partner a purchase order, but instead of wondering when she will respond, you can have an agreement with her that within 24 hours if you don’t get an answer, you will automatically send the order to another partner. This ensures that processes aren’t unreasonably delayed while an order sits unattended. This policy encourages the partner to create a process to accept, reject, or change the order within 24 hours. Because you are using SAP XI, you know that your processes will keep moving.

<<...in the next post we will discuss more about the comprising parts of XI...>>