Schedule % Complete Roll up Bar

Hi All,

I'm a relatively new user to P6 and a recurring problem that I'm having is that there is no roll up value for the schedule complete column, I've looked all over the web looking for a way to solve this but no success, the programme is resource and cost loaded and all other % completes are all fine apart from the schedule % Complete which is the main information which the client is looking for. Could someone please explain in the most basic terms how to get this rollup bar functional

Thank you in advance