Optimisation code

Sub Phase_in_out() 'mise à jour planification
  Dim J As Integer 'Date flottante
  Dim L As Long 'Première ligne vide dans la feuille "MILESTONE" avant remplissage
  Dim N As Long 'Première ligne vide dans la feuille "INOUT" avant remplissage
  Dim ShtI As Worksheet
  Dim ShtM As Worksheet
  ' Désactiver le recalcul et les évènements
  Application.Calculation = xlCalculationManual
  Application.EnableEvents = False
  ' Définir les objets feuilles sur lesquelles on travaille
  Set ShtI = ThisWorkbook.Sheets("INOUT")
  Set ShtM = ThisWorkbook.Sheets("MILESTONE")
  'Mise à jour de la feuille PHASE INOUT
  'Nettoyage de toutes les lignes avant mise à jour
  ShtI.Rows("7:15").Delete
  '
  For L = 3 To ShtM.Range("A11").End(xlUp).Row
    N = ShtI.Range("A15").End(xlUp).Row + 1
    ShtI.Range("A2:BD2").Copy Destination:=ShtI.Range("A" & N)
    ShtI.Rows(N).RowHeight = 12.75
    ShtI.Range("A" & N).Value = ShtM.Range("A" & L).Value
    
    For J = 3 To 81
      If ShtI.Cells(3, J) >= ShtM.Range("B" & L).Value And ShtI.Cells(3, J) < ShtM.Range("C" & L).Value Then
        ShtI.Cells(N, J) = 1
        With ShtI.Cells(N, J).Interior
          .Pattern = xlSolid
          .PatternColorIndex = xlAutomatic
          .ThemeColor = xlThemeColorDark1
          .TintAndShade = -0.249946592608417
          .PatternTintAndShade = 0
        End With
      End If
      If ShtI.Cells(3, J) >= ShtM.Range("C" & L).Value And ShtI.Cells(3, J) < ShtM.Range("D" & L).Value Then
        ShtI.Cells(N, J) = 2
        With ShtI.Cells(N, J).Interior
          .Pattern = xlSolid
          .PatternColorIndex = xlAutomatic
          .ThemeColor = xlThemeColorAccent4
          .TintAndShade = 0.399945066682943
          .PatternTintAndShade = 0
        End With
      End If
      If ShtI.Cells(3, J) >= ShtM.Range("D" & L).Value And ShtI.Cells(3, J) < ShtM.Range("E" & L).Value Then
        ShtI.Cells(N, J) = 3
        With ShtI.Cells(N, J).Interior
          .Pattern = xlSolid
          .PatternColorIndex = xlAutomatic
          .ThemeColor = xlThemeColorAccent5
          .TintAndShade = 0.399945066682943
          .PatternTintAndShade = 0
        End With
      End If
      If ShtI.Cells(3, J) >= ShtM.Range("E" & L).Value And ShtI.Cells(3, J) < ShtM.Range("F" & L).Value Then
        ShtI.Cells(N, J) = 4
        With ShtI.Cells(N, J).Interior
          .Pattern = xlSolid
          .PatternColorIndex = xlAutomatic
          .ThemeColor = xlThemeColorAccent2
          .TintAndShade = 0.399945066682943
          .PatternTintAndShade = 0
        End With
      End If
    Next J
  Next L
  ' Effacer les variables bojet
  Set ShtI = Nothing: Set ShtM = Nothing
  ' Réactiver le recalcul et les évènements
  Application.Calculation = xlCalculationAutomatic
  Application.ScreenUpdating = True
End Sub