The main challenge faced by Oracle Fusion Application is tracking users and applying correct roles and privileges. Users with unnecessary privileges can cause issues and trigger unsubscribed SKUs. Bundling of privileges in roles/groups can be challenging as not all users require full privileges. Lack of role segregation makes it difficult to report specific SKU use. Generic users, double counting users, and users assigned to subscriptions they don't need are also issues. Service Usage Metrics Reports should be used with care and expertise in interpretation. These issues lead to over-usage of cloud subscriptions and unnecessary spending. Appropriate asset management can prevent these issues.