Modifying measures in Dial View changes zones, etc. losing thus the last definition.
I think it's better when one defines zones, the user should define number of zones and, based on max-min values, automatically calculates values of each zone (100% / zones)
Then, based on this, it is faster to modify zones if necessary.
Another problem is that if you change 'maximum/minimun' in one zone, the normal thing is to change 'minimum/maximun' value from next/previous zone, and in the actual version it's not so easy.