Changing a Resource into a different Resource.
Resources can be released as a different "Resource". This makes it possible to indicate particular conditions to parts of the simulation.
For example: If a doctor always completes two Activities in sequence ("Operate" and "Clean Up") then the operating theater Activity could require a Resource "Doctor" but release this Resource as "Doctor A". A separate Activity (perhaps called "Cleansing") could require a Resource "Doctor A" and release a Resource "Doctor" - who is then ready to perform another operation.
