  Here we shall consider a very popular practical applied problem of managing
mode switching (in this work we are considering managing billing plans). Out of
the two parties (service provider and service consumer), participating in the
processes modelled here, we shall consider only a consumer type of a problem.
Herein we provide formal characterization of the problem as well as the
elements necessary for its solution. We shall consider full predicted costs,
originating when switching to a billing plan as a target index. The work
contains an example that provides a detailed view of the application technology
referring to the suggested problem solution algorithm. Using the example's data
we have performed the analysis measuring the problem's sensitivity in relation
to the growth of the traffic volume. Herein we provided a polynomial
approximation of the target index value depending on the traffic volume.
