A word of caution regarding archiving Cis.
Regarding implementing the data archival requirement, Servicenow has a known error because of which it cannot archive relationships, a workaround is available using which we can only archive parent CI and relationship but not the child ci so only half archiving of Ci relationships is possible.
KB reference : https://hi.service-now.com/kb_view.do?sysparm_article=KB0695364
Having said that, if we want to proceed with this approach first we need to have a strategy to handle relationships before archiving a CI.
I have seen customers having a logic that will validate that related CIs have correct relationships with latest Cis and delete the relationships with CIs that are not discovered (lets say for period of 6 months) hence making them good candidates for archival or purge.
For example if we have a Relationship1 tomcat server (tom1) RunsOn:Runs a linux host (Linux1), and if the host is not discoverable anymore, then we need to check if the Tomcat server (tom1) has relationship which any other linux host (Linux2) as Relationship2 in which case it proves that the Tomcat server(tom1) has a valid relationship to a host ( in this case Linux2 and relationship = relationship2) hence relationship 1 can be deleted as it not valid anymore.
