EXCEL VBA - Select Case - Index / Match - excel

Question

I have a spreadsheet which contains a massive IF then Formula and it's getting a bit out of control, the spreadsheet is getting slower and becoming more difficult to maintain.
Is it possible to move the formulas from the cells to VBA? Would this have any improvement on performance? I was thinking about using a Select Case but need some help as to whether a select case would work. The select case will need to look at multiple cells i.e. If A1 = Yes AND A2 = "Cash" AND A3 = No" then call the Index Match function to retrieve the value. Is this possible?
Is there a big performance gain moving formula's out of the worksheet into VBA?
Thanks for any advice.
Brett

Answer 1

I don't think you find any performance improvement simply from moving the same code from the cell into VBA.
However it will be easier to read, and you may then see that not all of the conditionals are necessary, so you may be able to simplify it - which would speed it up.
"Select Case" will probably not be helpful though as it can only be used for a single comparison, not three like you mention.
I would suggest taking it one step at a time, move the formula into VBA, and convert it to a VBA "if" statement. Then you may be able to see ways to tidy it up.

Answer 2

Yes and No.
The main advantage to using VBA is that you could then also use for or while loops.
So instead of writing the same formula for each cell, you can develop your code to do these calculations in as many cells as you need/want.
Its not an easy question to answer, due to the little amount of information provided in the question.

Answer 3

Having the code in Excel formulas mean that it will be recalculated when any of its parameters changes i.e. you change the value of one Excel cell -> all Excel cells that use this value will be recalculated. This may significantly slow down Excel when you are making constant changes.
One way of handling this is to manually turn off Automatic calculations (Formulas->Calculation Options->Manual). Make your changes and run the calculations manually by hitting Formulas->Calculate Now for recalculating the whole workbook or Formulas->Calculate Sheet for a recalc of only the worksheet.
Another way is to move the formulas to a VBA procedure. This way you can execute the calculation manually while all the other calculations in the workbook are carried out automatically.
EDIT1:
To make an VBA procedure from an Excel formula create a procedure like this:
Sub CalculateFormula
Range("A1").Value = Evaluate("YOUR EXCEL FORMULA WITHOUT '='")
'Simple example below
Range("A1").Value = Evaluate("IF(A1=1,1,2)")
End Sub
EDIT2:
With looping:
Sub CalculateFormula
for i = 1 to 10
Range("A" & i).Value = Evaluate("IF(B" & i & "=""Hello"",2,1)")
Next i
End Sub