This document outlines the steps to migrate from Oracle Enterprise Manager 10g to 12c Cloud Control. It discusses upgrading the Oracle Management Service (OMS) and repository database while keeping downtime minimal using a two-system upgrade approach. The process involves deploying 12c agents, backing up the 11g repository, upgrading the OMS to 12c on a new host, and migrating the agents to the new OMS with only brief downtime. Post-upgrade tasks include configuring a database link and stopping the old OMS.