Document ID Service Feature not found

Though we were using SharePoint 2010 enterprise version, I could not find the Document ID Service Feature in one of our Web Application’s site collection. There may be a script that can help to enable it, but I found codeplex’s SharePoint Manager 2010 helpful, so depicted the steps below:

1. Open SharePoint 2010 Manager tool, expand _SharePoint_Config node and expand Feature Definitions as depicted below:

2. Look for Document ID service feature (DocId), right lick on it and select install as depicted below:

After install, this should show the Document ID Service feature under the site collection features