Option Explicit
Sub TA()
Dim T, s$, n As Byte, i As Byte
T = Array("PT", "ECA", "ESA", "ETS")
Application.ScreenUpdating = 0
For i = 1 To 4
ActiveSheet.Shapes("cbTA" & i).Select
If Selection.Value = 1 Then s = s & T(i - 1) & ", "
Next i
n = Len(s): If n > 0 Then s = Left$(s, n - 2)
['Bilan ECA'!A2] = s: ActiveCell.Select
End Sub