Add the <pick> activity by dragging-and-dropping it to the BookWarehousingBPEL process. Place it immediately after the <invoke> activity within the WarehousingConfirmationInvocation scope. We should see the <pick> activity with a single OnMessage branch:

Double-clicking on the OnMessage icon opens the dialog box, where we need to specify the Partner Link, Port Type, and Operation:

Similarly, we will create the variable on the fly, using the green plus sign icon. We will create a local OnMessage_onResult variable:

To handle the response, we will place an <if> activity within the OnMessage scope. Within the <if> activity, we will check whether the books have been successfully warehoused. The corresponding XPath condition should look as follows:

For each branch, we will use an <assign>, where we will assign a successful or unsuccessful warehousing...