  The quasi-Heisenberg picture of minisuperspace model is considered. The The
quasi-Heisenberg picture of minisuperspace model is considered. The suggested
scheme consists in quantizing of the equation of motion and interprets all
observables including the Universe scale factor as the time-dependent
(quasi-Heisenbeg) operators acting in the space of solutions of the
Wheeler--DeWitt equation. The Klein-Gordon normalization of the wave function
and corresponding to it quantization rules for the equation of motion allow a
time-evolution of the mean values of operators even under constraint H=0 on the
physical states of Universe. Besides, the constraint H=0 appears as the
relation connecting initial values of the quasi-Heisenbeg operators at $t=0$. A
stage of the inflation is considered numerically in the framework of the
Wigner--Weyl phase-space formalism. For an inflationary model of the ``chaotic
inflation'' type it is found that a dispersion of the Universe scale factor
grows during inflation, and thus, does not vanish at the inflation end. It was
found also, that the ``by hand'' introduced dependence of the cosmological
constant from the scale factor in the model with a massless scalar field leads
to the decrease of dispersion of the Universe scale factor. The measurement and
interpretation problems arising in the framework of our approach are
considered, as well.
