Figured it might be useful to write this down and share. You can use the business service simulator (Site Map -> Business Service Admin -> Business Service Simulator) to test inbound integration based on a business service without the need for a harness or html stub. This is especially useful for debugging the scripts line-by-line. Here are the steps:
1. Find the xml message that you want to test and modify the file such that the xml is all in one line (no line feeds or carriage returns!) like this (it will be pasted into a Siebel field)
2. Log into Siebel as administrator and navigate to the bus svc simulator view.
3. In the Service Methods top applet, click New and select the business service and method you want to test. In this example, I am testing the inbound Contact message.
4. In the Input Property Set applet, type “Inputs” into the Type field and paste the xml you modified in step 1 into the Value field.
5. In the top Service Methods applet click “Run”
6. If you’ve put break points in your code, you can now step through the business service!