This is an interesting question. In my opinion, it may depend on the type of changed specifications and how that may affect the device. If it is a change in a minor detail of the aesthetics of the device, it can just require only the regression test on that one changed specification. But if the change involve a major part or function of the device as mentioned by Fady, that can require a further analysis. For instance, if the changed specification impacts a major part and a few other depending features of the device, it may need further investigation to see if it is truly required. Because with any change, you still have to confirm the main purpose of the device still meeting up to user’s needs, the safety and efficacy.