Flat shunting is a type of discrete event systems in the process of railway dispatching.It is very important that software of any flat shunting system have high reliability and high testability for ensuring transportation safety.For that goal

it is necessary to build a kind of regular design methods for software of flat shunting systems.In this paper

the complexity of event driving in the process of flat shunting and the limitation of description with natural language are analyzed.Therefore new descriptions of some processes in a flat shunting system with automaton models are proposed.In detail

the relationships between a flat shunting system and timed automata (TA)

pushdown automata (PDA) and the structure of layered automata are discussed.On the basis of explaining the partition of states

the data structure and the flow of state transition

a design method of flat shunting systems based on automaton models is built.