Distinguishing Sequences for Distributed Testing: Preset Distinguishing Sequences

2020-04-08T14:03:23Z (GMT) by Robert M Hierons Uraz Cengiz Türker

There has been long-standing interest in automatically generating test sequences from a finite state machine (FSM) and more recently this has been extended to the case where there are multiple physically distributed testers and so we are testing from a multi-port FSM. This paper explores the problem of generating a controllable preset distinguishing sequence (PDS) from a multi-port FSM, motivated by the fact that many FSM-based test generation algorithms use PDSs. We prove that it is generally undecidable whether a multi-port FSM has a controllable PDS but provide a class of multi-port FSMs for which the problem is decidable. We also consider the important case where there is an upper bound on the length of PDSs of interest, proving that controllable PDS existence is PSPACE-hard and in EXPSPACE. In practice the upper bound is likely to be a polynomial in terms of the size of the multi-port FSM and in this case controllable PDS existence is NP-Complete.