  One widely used technique for the construction of equilibrium models of
stellar disks is based on the Jeans equations and the moments of velocity
distribution functions derived using these equations. Stellar disks constructed
using this technique are shown to be "not entirely" in equilibrium. Our attempt
to abandon the epicyclic approximation and the approximation of infinite
isothermal layers, which are commonly adopted in this technique, failed to
improve the situation substantially. We conclude that the main drawback of
techniques based on the Jeans equations is that the system of equations
employed is not closed, and therefore requires adopting an essentially ad hoc
additional closure condition. A new iterative approach to constructing
equilibrium N-body models with a given density distribution is proposed. The
main idea behind this approach is that a model is first constructed using some
approximation method, and is then allowed to adjust to an equilibrium state
with the specified density and the required parameters of the velocity
distribution remaining fixed in the process. This iterative approach was used
to construct isotropic, spherically symmetric models and models of stellar
disks embedded in an external potential. The numerical models constructed prove
to be close to equilibrium. It is shown that the commonly adopted assumption
that the profile of the radial velocity dispersion is exponential may be wrong.
The technique proposed can be applied to a wide range of problems involving the
construction of models of stellar systems with various geometries.
