A set of systems are considered where there are multiple agents simultaneously active within real-time a environment. These systems are termed SMART systems and are found in domains as diverse as office administration, process control and aviation. Such systems place particular demands on agents that are not present in non-SMART systems. Actions may be time constrained in two ways: i) an action appropriate at one time may not be appropriate at another; ii) the time available for a required action may approximate to the time in which an agent is able to perform that action. In order to be able to function in such environments agents, both human and computer, must be aware of time constraints and the actions necessary to ensure that they do not compromise system goals.