Ok, that's SAP Invoice Management by OpenText addon. OSS has a precious few notes concerning installation of addon or upgrade of SAP Systems containing this addon (found using search term OTEXVIM):
1920804 - SAP Invoice Management by OpenText support for EhP7
1721041 - SAP Invoice Management by OpenText support for EhP6
1262124 - Vendor key handling in ERP Enhancement Packages 3 and 4
1353761 - SAP Invoice Management by Open Text 5.2
1143354 - SAP Invoice Management by Open Text
They concern for the most part only the compatibility of OT releases with SAP releases; you'll not find information on how the Open Text BADI implementations should be handled during upgrades, how they should be named, etc. That info may, however, be contained in something called "OpenText Vendor Invoice Management x.x.x. - Configuration Guide" documents - I came across one such document in google search.
If documentation does not help, I'd suggest to contact OpenText support. If that is not an option, or if there is time pressure, I'd first try to handle it just like any other custom BADI implementation - meaning, option 2 in SPAU, creating new custom enhancement implementation (it should be for enhancement spot UPDATE_INVOICE though, I believe...). That should hopefully permit to create implementation in customer namespace and test, if the functionality is ok. Then, when the info from Open Text comes - do as they say.
cheers
Janis
Message was edited by: Jānis B
EDIT IN once again:
Nope, an attachment to 1791874 - SAP Products by OpenText - Software and Support Lifecyclesays that "SAP Customer Support handles all OpenText related support queries"... so. I dont know... I'd be contacting OSS in your place.
Message was edited by: Jānis B