To Add a SAP BPM System as a Task Provider:
Define trust between SAP Gateway and the AS Java system.
Create a Web service proxy port to connect to the SAP BPM System. To do so:
Log on to the Gateway system.
Run transaction SOAMANAGER.
Navigate to Service Administration→Web Service Configuration. Search for Consumer proxyTASK*.

Click on the resulting link: /IWPGW/CO_BPM_TASK_FACADE.

Select Create→Manual Configuration, enter a Logical Port Name, and click Next.

Select SAP Authentication Assertion Ticket and click Next.

Enter URL Access path, Computer Name of Access URL, Port Number of Access URL, andURL Protocol Information and click Finish.

Choose Ping Web Service to test the connection.

Create an SAP system alias to be used by the Taskprocessing service. To do so:
Navigate to SAP Reference IMG→ABAP Platform→SAP Gateway→OData Channel→Configuration→Connection Settings→SAP Gateway to SAP System→Manage SAP System Aliases.

Choose New Entries.

Enter the following details for the system alias and then save your settings.
Details for the System Alias
Field Description SAP System Alias
Unique Name of the system alias
Description
Descriptive text for the system alias
For local app
Check the box
RFC Destination
None
Software Version
For BPM : /IWPGW/BPM
WS Provider System
Web Service proxy logical port name

Save.
Assign SAP System alias to the Taskprocessing OData Service as per the previous description To Add a BWF System as a Task Provider.