Robust dynamic exchange of implementation aspects

We show a technique for consistent dynamic exchange of different aspects of implementations of abstract data types, in particular data structure representations and algorithms. Previous work showed how one single aspect's implementation can be exchanged dynamically without running into robustness problems if other aspects are guaranteed to be fixed. The present work generalizes this idea in the sense that all aspects' implementations may be exchanged arbitrarily at run time where robustness is preserved. We use finite state machines where each state represents a combination of the different implementations and each transition an exchange of exactly one aspect's implementation. We use these state machines to check for the robustness of a class within a certain application context.