Exposing a Decision Table as a Web Service 
You can expose a decision table of a reusable ruleset as a Web service. Therefore, you need not always use the if-then rule to execute the decision table but execute the decision table independently from any system.
In the Project Explorer view, expand the rules composer DC node.
Expand the Rules Modeling node.
Select the required decision table from a Reusable Ruleset.
From the context menu of the decision table, choose .
In the dialog box that appears, change the service name, port name, and operation name, if required.
Choose Next.
Select the input and output schemas for the Web service.
Choose Finish.
The system creates a Web service file (<ruleset name>-<decision table name>.csdl) for the decision table under the folder location .
Deploy the rules composer DC.
More information: Deploying Rules