In Anaplan's new UX, when running an extended process, any user active may be greeted my a banner informing them that the '… Model is Busy'.
However, this message can be ambiguous, and it may be beneficial for certain processes to more clearly articulate what is happening. My suggestion would be the ability to add a new dimension to Processes and Actions, which allows users to type in text that will override this default message for users in the new UX.