Sub FollowEarliestPredecessor()
Dim t, p, earliest As Task
Dim ps As Tasks
Dim l As Long
Dim tdeps As TaskDependencies
Dim tdep As TaskDependency

Set t = ActiveSelection.Tasks(1)

'Set lag to 0 to remove any previous lags
Set tdeps = t.TaskDependencies
For Each tdep In tdeps
     If tdep.To = t.ID Then
          tdep.lag = 0
     End If
Next tdep
CalculateProject

'Find earliest predecessor
Set ps = t.PredecessorTasks
Set earliest = ps(1)
For Each p In ps
    If p.Finish <= earliest.Finish Then
        Set earliest = p
    End If
Next p

'Set lag so it covers the greatest task variance
l = -Application.DateDifference(earliest.Finish, t.Start)

'Apply that lag to all predecessors except for the earliest
For Each tdep In tdeps
    If tdep.To = t.ID And tdep.From <> earliest.ID Then
        tdep.lag = l
    End If
Next tdep
CalculateProject

End Sub