Interacting with BTS processes and activities

You can use BTS processes and activities to interact with the world outside the BTS environment. A program running outside a process can use BTS to acquire access to an activity in the process.

In the examples we have looked at so far, after the initial order details are collected from a user terminal the Sale business transaction proceeds without further interaction with the outside world. Each activity is started automatically by CICS® business transaction services, following the completion of its predecessor.

In practice, many business transactions require some external interaction. For example, most business transactions include activities that require human involvement. These activities are known as user-related activities . User-related activities cannot be started automatically by BTS, because they rely on the user being ready to process the work. Other examples of external interactions are dependencies on input from the World Wide Web or from IBM® MQ queues.

For example, the CICS transactions can:

Use BTS processes as servers: A client transaction outside a process can “acquire” the root activity of the process. This enables it to pass business data to the process in the process or root activity's containers. The transaction does not become part of the process - rather, it is able to activate the process and use it as a server.
Acquire BTS activities: A transaction outside a process can acquire a descendant activity within the process. Acquiring the activity gives the transaction access to the activity's containers, and allows it to activate the activity.

Both these examples use input events to signify that a process or activity requires some external interaction to take place before it can complete.