Models exist to answer "what if?". A scenario switch lets one cell flip the whole model between cases, such as Base, Upside and Downside, without editing a single formula.
Lay out each driver once per case, side by side, and add a live case column that picks the active value:
=CHOOSE($B$3,C6,D6,E6) returns the first, second or third value, depending on the number in the switch cell B3.=INDEX(C6:E6,$B$3) does the same from a range, and is easier to extend when you add a case.- With the case name in the switch cell, add MATCH:
=INDEX(C6:E6,MATCH($B$3,$C$5:$E$5,0)).
Every forecast formula then points at the live column, never at a case column directly. Lock the live cells with $ so the forecast fills cleanly across the years.
The case values are inputs, so they stay blue; the live column is formulas, so it's black. Changing the switch should be the only thing anyone needs to do to see another case.