Derivation of optimum test sequencies for sequential machines

A technique is presented for deriving the shortest sequence of input symbols which must be applied to a sequential machine to guarantee that no fault from a set {p} exists within the machine. Flow tables are used to describe the machine for which a test is desired as well as all defective machines into which it is transformed by the faults of {p}. The set of flow tables is combined into a single composite table from which the optimum test sequence is found. Use of a composite table has the advantage that all possible sequences of input symbols need not be investigated. A large class of sequences which cannot possibly lead to an optimum test is easily recognized and discarded.