Testing is complete?
Testing is never complete. This emplies that the software that is deployed is perfect and will never need to be patched or updated.
In the real world, the vendor will continue to release patches from time to time to fix issues, and over time will release new versions of the software whilst dropping support for old versions. For any mission-critical software, it's important that every single patch and update is tested before being deployed - especially as lots of ERP apps have various customisations added for different customers, and you need to ensure that the patches/updates don't interfere with anything important.
For this reason, you always need a test version to be available to a specially chosen group of staff.
Biting the hand that feeds IT
