.Model.ModelRelationships.Add loop how to speed up script

[Belina65]

Hello,

I'm a java backend developer (spring an so on) I know nothing about visual basic scripts in Excel, at work they gave me a task to speed up this script (ROTFL),
The execution time is about 6-8 hours. I read that accessing data from a loop is a bad practice, Please help me on how to speed up this (using regions perhaps ? ), Thank you.

Sub CREATE_RELATIONSHIPS(ByRef wb As Workbook)

    Dim sh As Worksheet
    Dim rw As Variant
    Dim RowCount As Integer
    Dim PK_T As String, PK_C As String, FK_T As String, FK_C As String
    Const CREATING_RELATION_CONST = "Creating Relationship "
    Dim start As Double
    Dim realationsCounter As Long
    start = Timer
    RowCount = 0
    
    Set sh = wb.Sheets("Relations")
    
    For Each rw In sh.Rows
      If sh.Cells(rw.Row, 1).Value = "" Then
        Exit For
      End If
      
      If RowCount >= 1 Then
        FK_T = sh.Cells(rw.Row, 1).Value
        FK_C = sh.Cells(rw.Row, 2).Value
        PK_T = sh.Cells(rw.Row, 3).Value
        PK_C = sh.Cells(rw.Row, 4).Value
        
        Debug.Print CREATING_RELATION_CONST, FK_T, FK_C, PK_T, PK_C
        'On Error Resume Next
        wb.Model.ModelRelationships.Add wb.Model.ModelTables(FK_T).ModelTableColumns(FK_C), wb.Model.ModelTables(PK_T).ModelTableColumns(PK_C)
        realationsCounter = realationsCounter + 1
        'If Err Then
        '    Debug.Print "Error"
        'Else
        '    Debug.Print "Created relationship"
        'End If
        
      End If
      RowCount = RowCount + 1
    Next rw
    
    Debug.Print realationsCounter, " relations created."
End Sub

thank you very very much