  A system of a metastable phase with several sorts of the heterogeneous
centers is considered. An analytical theory for the process of decay in such a
system has been constructed. The free energy of formation of the critical
embryo is assumed to be known in the macroscopic approach as well as the energy
of solvatation. The process is split into some periods and the analytical
description of every period is given. The most difficult to describe is the
period of the essential formation of the embryos of a new phase. At first some
asymptotes are investigated and then a general solution is suggested. Several
approximate transformations are accomplished with the corresponding numerical
estimates and some analytical justifications.
