Minimizing the formula.

Hi,

Please try something like below whether it suits your requirement.

Current Month Average =
SWITCH (
    'Table'[Tracking Parameters],
    "PO Receipt to SO Creation", AVERAGE ( Sheet1[PO Receipt to SO Creation] ),
    "SO Creation to SO Release", AVERAGE ( Raw[SO Creation to SO Release] ),
    "SO Release to SO Planning", AVERAGE ( 'TAT Report'[SO Release to SO Planning] ),
    "Planning to Vehicle Reporting", AVERAGE ( 'TAT Report'[Planning to Vehicle Reporting] ),
    "Vehicle Reporting to Vehicle GateIn", AVERAGE ( 'TAT Report'[Vehicle Reporting to Vehicle Gate In] ),
    "Vehicle Gate In to Vehicle Gate Out", AVERAGE ( 'TAT Report'[Vehicle Gate In to Gate Out] ),
    "Dispatch To Delivery", AVERAGE ( 'TAT Report'[TAT 9 Transit Time (Dispatch to Delivery)(Hours)] ),
    0
)