Option Explicit
Sub Essai()
Dim dlg&, lig&: Application.ScreenUpdating = 0
dlg = Cells(Rows.Count, 2).End(xlUp).Row
If dlg = 1 And IsEmpty([B1]) Then Exit Sub
For lig = 1 To dlg
With Cells(lig, 2)
If InStr(.Value, "S11") > 0 Then
.Offset(, -1) = "S11": .Offset(, 9) = "S11"
Else
.Offset(, -1) = Empty: .Offset(, 9) = Empty
End If
End With
Next lig
End Sub