Formal evaluation of diagnostic sequences of digital devices

The paper proposes a formal mathematical apparatus for evaluation of the quality of diagnostic sequences of digital devices described at the structural level. To achieve this, the functions of behavior of devices at structural level are introduced: setting of the component to the prescribed value, activity and distinguishing activity on pair or set of components. The use of the introduced formalism for constructing evaluation functions for the most commonly used diagnostic sequences is demonstrates. The possibility of extension of apparatus on the three valued logic is shown. Application of constructed mathematical apparatus allows formalizing information about device behavior at the structural level, to more accurately evaluate of the constructed sequence and to improve the convergence of methods for generating of diagnosing sequences of different types.