In this paper we shall introduce two equivalent tech-
niques in order to evaluate reliability analysis of electrical aircrafts
systems (EAS): (i) graph theory technique, and (ii) simplifying dif-
feomorphism technique. Geometric modeling of reliability models
is based on algebraic hypersurfaces, whose intrinsic properties are
able to select those models which are relevant for applications. The
basic idea is to cover the reliability hypersurfaces by exponentially
decay curves. Most of the calculations made in this paper have
used Maple and Matlab software.