  Geometric modeling of multivariate reliability polynomials is based on
algebraic hypersurfaces, constant level sets, rulings etc. The solved basic
problems are: (i) find the reliability polynomial using the Maple and Matlab
software environment; (ii) find restrictions of reliability polynomial via
equi-reliable components; (iii) how should the reliability components linearly
depend on time, so that the reliability of the system be linear in time? The
main goal of the paper is to find geometric methods for analysing the
reliability of electric systems used inside aircrafts.
