what is the use of replace on upgrade in update set?

[Manikantahere]

[Simon Christens]

Hi

It means that if you customize something then it will be overwritten back to OOB when you upgrade.

In this case you can make customizations as workarounds that will be fixed on the next upgrade for ex - then it auto replace the customization instead of you needing to go into upgrade monitor and revert it back to OOB.

[GusPosadaFlorez]

https://www.servicenow.com/docs/csh?topicname=t_OverwriteCustomizsDuringUpgrades.html&version=latest

Specify which customized objects you want to replace during the next upgrade. By default, the upgrade process skips changes to customized objects.