A 32bit SSIS Execution Method may be created by building a new SSIS_32 off of the base SSIS Execution Method.

1. Navigate to the Execution Methods Shortcut, then click the Add button.
2. Name the new Method. This example uses "SSIS_32". Add a description as desired.
3. Select SSIS for the Base Method.
4. Ensure Edit After Adding is checked, then click Ok.
5. The Execution Method Dialog will appear. Select the Properties tab, then edit the Command field to reference the path to the 32 bit executable.
   

A Job may now be created using this new Execution Method and it will use the specified executable at run-time.