David,
Several ideas come to mind, some may be realatively simple while others
are more sophisticated.
Let me start with the simple. Although I've never used this field, there
is a field called "Update needed". Depending on how well the file is
maintained, all that may be necessary is to monitor this field to see if
the update has been made by the consultant(s). It is possible there is
one or more other fields that through clever monitoring could detect an
update but I quite honestly don't know what fields those might be and it
would take some time to figure out a monitoring scheme.
The next level of sophistication (and more robust) is to first save the
file just prior to sending out for update. Then after updates are
returned, run the "compare Project versions" add-in to see the changes.
If you do not have the add-in, it is available from the MS webpage at:
http://office.microsoft.com/officeupdate
If you try this method and it just doesn't quite give you the output you
need or like there are other compare macros that may be available (i.e.
output in color). If interested, write me direct for more information.
The third method is similar to the above but is a little less robust.
Use spare fields to store a snapshot of relevent project data. For
example, use Start1 and Finish1 to store Start and Finish, Duration1 to
store Duration, etc. You can then run a relatively simple macro to test
these values when the updated file is returned. The macro can even
highlight the changed values in color.
There are a few ideas to get you started.
John