Has anybody done much integration work around work orders (MFG object)?  We have a requirement to remove and add materials to a work order after it has been created.  We have been successful in doing this by marking the materials that are no longer needed as excluded, which shows them as cancelled on the work order, and then by adding new materials as if they are unexpected materials.  The issue is, as soon as we do the automatic release, it marks all of the original materials from the BOM as active/included again, and it removes the ones that were manually added.  Has anybody done anything similar to this?  I was thinking of using the MFG object as a web services, and seeing if there is an option to do the line logic (exclude or add unexpected materials) as a web service call.