What is the reason you cannot add a close incident to a problem record in ServiceNow OOB. This is a common point of confusion in ServiceNow and in ITIL practices more generally. Let’s unpack this carefully:

The Situation

You’ve got:

• A Problem record — used to identify and eliminate the root cause of one or more incidents.
• One or more Incidents — which are user-facing interruptions or degradations of service.

In ServiceNow, you can link incidents to a problem record (via the “Related Incidents” list) so that all related incidents are associated with the same underlying problem.

Why you can’t (or shouldn’t) add a closed incident to a problem

In out-of-box ServiceNow configurations, you cannot relate closed incidents to a problem record —

The main reasons are process and governance:

1. ITIL best practice encourages proactive problem management
   
   • Problem investigation should start while incidents are active or recently resolved.
     
   • Once incidents are closed, they’ve already gone through their lifecycle — reopening them or attaching them to a problem after closure can complicate metrics and reporting.
2. Data integrity and reporting concerns
   
   • Attaching closed incidents later can skew KPIs such as “mean time to resolve” or “number of incidents per problem.”
     
   • Many organizations lock closed incidents from further modification to ensure audit consistency.
3. Workflow and automation design
   
   • ServiceNow workflows often trigger notifications, updates, and status changes when incidents are linked to problems.
     
   • Doing this retroactively on a closed record may trigger unintended actions or break automation sequences.

What is the ITIL stance

ITIL does not strictly forbid linking closed incidents to problems. However:

• Proactive Problem Management (identifying issues before they recur) focuses on open or recent incidents.
• Reactive Problem Management (after incidents occur) can include analysis of closed incidents for trend analysis — but this is typically done via reporting and analytics, not by re-linking old incident records.

So, it’s not “against ITIL”, but it’s usually against local process controls designed to preserve clean data and audit trails.