It's all about IAM

Identity And Access Management - Rajiv Dewan

Enetitlement Revocation Information

Something to share (OIM 11g R2 PS1):

If entitlements get provisioned to users, we can verify from the Entitlement Tab under User Details but if entitlement gets "Revoked" from a user, there's no way to find that information from OIM User Interface (Enhancement request can be opened with Oracle).

OIM is a tool for Auditing so I believe that it stores that information somewhere but Where ???

"ENT_ASSIGN_HIST". It contains a column called "VALID_TO_DATE" which stores the Revocation Date.