Option Explicit
Sub Essai()
Dim cel As Range, pdt$, qt1%, qt2%, m&, n&, i&, j&
m = Rows.Count: n = Cells(m, 7).End(3).Row: j = 2
Application.ScreenUpdating = 0
If n > 1 Then Range("G2:H" & n) = Empty
n = Cells(m, 1).End(3).Row
For i = 2 To n
pdt = Cells(i, 1): Cells(j, 7) = pdt
Set cel = Columns(4).Find(pdt, , -4163, 1, 1)
If Not cel Is Nothing Then
qt1 = Cells(i, 2): qt2 = cel.Offset(, 1)
Cells(j, 8) = IIf(qt1 = qt2, "identique", Format(qt2 - qt1, "+0;-0"))
Else
Cells(j, 8) = "manquant"
End If
j = j + 1
Next i
n = Cells(m, 4).End(3).Row
For i = 2 To n
pdt = Cells(i, 4): Set cel = Columns(1).Find(pdt, , -4163, 1, 1)
If cel Is Nothing Then
Cells(j, 7) = pdt: Cells(j, 8) = "nouveau ; " & Cells(i, 5): j = j + 1
End If
Next i
End Sub