What happens if I update an Out Of the Box script, business rule etc.?

This question was wondering around inside my head for quite some while. The simple answer that I got and it was hard to find more about it was: It doesn't get updated when ServiceNow releases a new patch or release.

Well, that is a start. But then again. Can I somewhere see what will be excluded from an upgrade. After been configuring ServiceNow for like 6 months and now been live for almost another 6 month, I finally starting to understand it more deeply how things work and starts to question if we shouldnt have done it in a different way instead. And I find stuff here and there that hasn't been done by the rule "do not edit copy existing rule instead and edit that".

After digging around and talking to HI-support I found out that everything that is excluded from an upgrade is stored in a particular table, which wasnt such a big surprise...

And this is how it works:

When for example a business rule was unmodified (OOB), it may be overwritten by a new version when patching/upgrading your service-now instance.
However when you modify the business rules, the specific record will be flagged as "customized".

When it's flagged as "customized" the system will:

1. Make a note of the face that customer has customized the record, this is stored in the "sys_update_xml"-table.
2. The system will NOT overwrite or change any records that are in this table (flagged as customized).

This means that when you patch or upgrade the instance, the records that are customized (have an entry in the sys_update_xml table) will NOT be overwritten.

So if there is an update to your business rule that you edited, it will not be overwritten because it's marked as "customized".

However, if you decide you want to undo this, then you can delete the found entry from the sys_update_xml table. When you then patch or upgrade your instance the business rule in this example will be overwritten with the OOB version.


And just to let you know... That table is filled with stuff you didn't think would be in there, so watch out =)