“…Therefore, in the literature most approaches that try to deal with the validation of dynamic software system concentrate the changes to the structure by using graph and graph grammars formalisms or topological constraints [11,23,25,30,32,39,14,22]. As far as changes to behaviour are concerned, only few approaches exist that make use either of behavioural equivalence checks or of the type system [2,3,4] or through code certification [12,33]. If dependability has to be preserved through adaptation, whatever the change mechanism is, at the time the change occurs a validation check must be performed.…”