Creating a Function Inventory for a Workbook

Tim has a workbook that is rather large, and he wonders if there is a way to do an "inventory" of which functions are used in the various formulas in the workbook, along with the cells in which those functions are used.

This task is a bit harder that it may at first seem. You can make some rules as to what constitutes an Excel function, but those rules can get a bit hinky. For instance, you might think that a function is defined by an uppercase word followed by an opening parenthesis. This hasn't been true for a while, however, as function names can now contain periods.

The easiest way that I've found to get a function inventory is to develop a macro that will step through each formula in each worksheet in the workbook and check that formula against every possible worksheet function. The following macro will do that just fine:

Sub FormulaInventory()
    Dim EFunc(500) As String
    Dim iEFCnt As Integer
    Dim sFile As String
    Dim sTemp As String
    Dim SourceBook As Workbook
    Dim TargetBook As Workbook
    Dim TargetSheet As Worksheet
    Dim w As Worksheet
    Dim c As Range
    Dim iRow As Integer
    Dim J As Integer
    Dim K As Integer
    Dim L As Integer

    ' Read functions from text file
    sFile = ActiveWorkbook.Path & "\ExcelFunctions.txt"
    iEFCnt = 0
    Open sFile For Input As #1
    While Not EOF(1)
        Line Input #1, sTemp
        sTemp = Trim(sTemp)
        If sTemp > "" Then
            iEFCnt = iEFCnt + 1
            EFunc(iEFCnt) = sTemp & "("
        End If
    Wend
    Close #1

    ' Sort functions; longest to shortest
    For J = 1 To iEFCnt - 1
        L = J
        For K = J + 1 To iEFCnt
            If Len(EFunc(L)) < Len(EFunc(K)) Then L = K
        Next K
        If L <> J Then
            sTemp = EFunc(J)
            EFunc(J) = EFunc(L)
            EFunc(L) = sTemp
        End If
    Next J

    ' Create and setup new workbook
    Set SourceBook = ActiveWorkbook
    Set TargetBook = Workbooks.Add
    Set TargetSheet = TargetBook.Worksheets.Add
    TargetSheet.Name = "Inventory"
    TargetSheet.Cells(1, 1) = "Function Inventory for " & SourceBook.Name
    TargetSheet.Cells(3, 1) = "Function"
    TargetSheet.Cells(3, 2) = "Worksheet"
    TargetSheet.Cells(3, 3) = "Cell"
    TargetSheet.Range("A1").Font.Bold = True
    TargetSheet.Range("A3:C3").Font.Bold = True
    With TargetSheet.Range("A3:C3").Cells.Borders(xlEdgeBottom)
        .LineStyle = xlContinuous
        .Weight = xlThin
    End With

    ' Perform actual inventory
    iRow = 4
    For Each w In SourceBook.Worksheets
        For Each c In w.Cells.SpecialCells(xlCellTypeFormulas)
            sTemp = c.Formula
            For J = 1 To iEFCnt
                If InStr(sTemp, EFunc(J)) Then
                    TargetSheet.Cells(iRow, 1) = Left(EFunc(J), Len(EFunc(J)) - 1)
                    TargetSheet.Cells(iRow, 2) = w.Name
                    TargetSheet.Cells(iRow, 3) = Replace(c.Address, "$", "")
                    iRow = iRow + 1
                    sTemp = Replace(sTemp, EFunc(J), "")
                End If
            Next J
        Next c
    Next w
End Sub

Careful examination of the macro indicates that it reads in a text file (ExcelFunctions.txt) that includes a listing of all of Excel's worksheet functions. This file can be downloaded by using this link, and it should be stored in the same folder as the workbook that you are analyzing. (This means that the workbook you are analyzing must have already been saved in a folder.)

When the worksheet function names are loaded from the text file, the macro appends an opening parenthesis to each name. These names are stored in an array, and then this array is sorted according to the length of the function name, with the longest function names at the beginning of the array. This is done because of some ambiguity in function names. For instance, when the function-name array is read in you'll have one function named LEFT( and another named T(. When looking at a formula, if the LEFT( name is found then the T( name will also be found. By looking at the longest function names first and then removing those names from the formula string, then you eliminate the possibility of "false positives."

It should be noted that this function will only work with those worksheet functions listed in the ExcelFunctions.txt file. You can modify the file, as desired, to adapt what is located. It currently includes all standard worksheet functions for Excel 2016, but you may want to modify it to include functions made available by your add-ins, or you may want to delete functions that you find too esoteric. (Hint: You could also simply add an apostrophe in front of a function name in the text file and it will then never be included in an inventory.) There are just below 500 function names in the file now; if you add too many more, you'll need to change the number elements declared in the macro for the EFunc array.

When the macro is completed, you'll find your inventory in the new workbook that the macro creates. You should note that the time it takes the macro to complete can vary from quite fast to amazingly slow. The larger your workbook—the more worksheets it contains and the more formulas on those worksheets—the longer it will take to finish its work. Remember it has to check every formula in the workbook against almost 500 worksheet function names.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (5136) applies to Microsoft Excel 2007, 2010, 2013, and 2016.