PLC▷GIT
Depending on your configuration the backup mostly is done in the night. This backup contains the code from the PLCs, and it includes for the remanent variables the current data value.
If the machine will not work as expected after some changes in the PLC program code choose a known state of the machine it it did work fine. This can be the original version, but mostly this is the running version from the previous week. Because ot the stored data values for the remanent values immediately after the program restore your machine works again as in the selected weel.