Testing of automata system

The problem of testing of aggregate systems is considered. The system is described with an oriented graph of links. The nodes correspond to automata of the components and arcs correspond to simplex communication channels. The hypothesis of the links is assumed: the graph of links is static and the link structure is error-free. In each state, the automaton can accept and send multiple messages through incoming and outgoing arcs (at most one message through each arc). The goal of testing is to cover transitions of the automata reachable during the system work. It assumed that during testing it is possible to observe the state changes of automata and the messages on the arcs. A simplified system model with only one message circulating is considered at the beginning. On its example we show that the hypothesis on links allows considerably reduce the number of required testing actions from the multiplication of numbers of the component automata states to the sum of these numbers. If the numbers of states of all automata are equal, it gives exponential reduction of the number of test actions. Then the more general model is considered when the system can simultaneously contain multiple messages, but not more than one on each arc. A composition of the system automata is defined and the restrictions on automata making the system deterministic are described. An algorithm of test generation is proposed basing on test filtration generated for covering all transitions of the deterministic composition system. Test is rejected if it covers only such transitions of the components that are covered by the remaining tests. In conclusion, the directions of future research are described.