Smart environments are places that contain numerous devices to assist a user. Those devices’ actions can be modelled as planning operators. A problem when modelling such actions is the persistent action problem: Actions are not independent of one another. This is especially relevant when regarding persistent actions: An action that is being executed over a longer timespan may be terminated by a subsequent action that uses the same resources. The question is how to model this adequately. In dynamic environments with a high fluctuation of devices an additional challenge is to solve the persistent action problem with as little global information as possible. In this paper, we introduce two approaches: The first one locks resources which are being used by an action to prevent other actions from using the same resources. The second interleaves planning and execution of actions and is thus able to use software agents as guardsʺ for actions that are being executed. We furthermore compare the characteristics of both approaches and point out some implications those characteristics have on the modelling and execution of device actions in smart environments.
