Optimising Measure for Speed

Try using variables and a SWITCH statement instead: 

Growth Label = VAR CashMarginDiffPositive = [Cash Margin DIFF]>0

VAR NetSalesDiffPositive = [Net Sales DIFF]>0

VAR MarginRateDiffPositive = [Margin Rate DIFF]>0

RETURN

SWITCH( TRUE(),AND(AND(CashMarginDiffPositive,NetSalesDiffPositive),MarginRateDiffPositive)=TRUE(),"Growing Everything",

AND(AND(CashMarginDiffPositive,NOT NetSalesDiffPositive),MarginRateDiffPositive)=TRUE(),"Growing Margin",

AND(AND(CashMarginDiffPositive,NetSalesDiffPositive),NOT MarginRateDiffPositive)=TRUE(),"Growing Sales",

AND(AND(NOT CashMarginDiffPositive,NetSalesDiffPositive),MarginRateDiffPositive)=TRUE(),"Logical Error",

AND(AND(NOT CashMarginDiffPositive,NetSalesDiffPositive),NOT MarginRateDiffPositive)=TRUE(),"Growing Sales, Declining Rate",

AND(AND(CashMarginDiffPositive,NOT NetSalesDiffPositive),NOT MarginRateDiffPositive)=TRUE(),"Logical Error",

AND(AND(NOT CashMarginDiffPositive,NOT NetSalesDiffPositive),MarginRateDiffPositive)=TRUE(),"Growing Rate, Declining Sales",

AND(AND(NOT CashMarginDiffPositive,NOT NetSalesDiffPositive),NOT MarginRateDiffPositive)=TRUE(),"Declining Sales","GAP")