Modelling Timeouts without Timelocks

We address the issue of modelling a simple timeout in timed automata. We argue that expression of the timeout in the UPPAAL timed automata model is unsatisfactory since when composed with a component behaviour, the timeout can generate timelocks. In response we consider an alternative timed automata framework - timed automata with deadlines. This framework has the property that timelocks cannot be created when composing automata in parallel. We explore a number of different options for reformulating the timeout in this framework and then we relate them.