Automatic Project "Phase" field update through completing task in the phase

I think it's a bit complicated to clear explain but i try..

I want in Project Center a field (Project Phase) that change value automatically when i complete the same phase in the gantt chart.

I'try with a Phase Level field (If Summary=Yes, and %Complete = 100, insert 1 else 0) but i can't rollup this value to the Project Summary Row to add a Project Field (If "Phase Level" = 1 than START, IF "Phase Level" = 2 than PLAN, etc.) maybe with Indicators, to show on the Project Center.

I need help please..

P.S. For the moment i resolve with Milestone Phase, so if i said the Milestone is a "Phase Milestone" and it's 100% it count 1.

Like in this Picture:

Thanks

Daniele