Interesting Properties of the Real-Time Conformance Relation

We are interested in black-box conformance testing of realtime systems. Our framework is based on the model of timed automata with inputs and outputs (TAIO). We use a timed conformance relation called tioco which is the extension of the untimed relation ioco. We show that considering only lazy-input TAIO is enough for describing all possible non-blocking specifications. We compare between tioco and the trace-inclusion relation. We prove that tioco is undecidable and that it does not distinguish specifications with the same set of observable traces. We prove tioco to be transitive and stable w.r.t both compositionality and action hiding for input-complete specifications. We compare between tioco and two other timed conformance relations, rtioco and tioco.