Approach to the estimation of the productive resources is examined, which are minimally necessary for the functioning of the information systems of enterprise with the territorially distributed branches (offices). During the estimation the apparatus of the busy periods of the system of queueing with the expectation is used. The proposed approach is directed toward the solution of the problem of the minimization of the human resources, of the productivity of servers and capacity of the circuits of the transmission of the data, spent on control of the information systems of the enterprise.