Application System Interfaces

Application can talk to other applications in real-time or in batch mode.

Many application systems have batch interfaces with other application systems.  An application interface allow one system to pass information or messages to a second application.

The application system that is invoked responds to the request with message indicating that the communication was successful or not.

Often, some sort of "middleware" is used to connect two applications.

The interaction occurs over a network using some type of communication protocol (e.g. FTP, HTTP, HTTPS).

Historically, it has been difficult to integrate application systems online.  The reason for this is that systems are built on different platforms using different technologies which are not designed for integration.

In recent years, many software vendors are beginning to support vendor-neutral technologies such as XML/SOA.  This is discussed in a later section.