This paper is concerned with two critical problems which are appearing during a design procedure of an Integrated Microprocessor-Based Control and Protection System to be applied in H.V. Electric Power Substations. Those problems are related to strategies for selection of distributed architecture and allocation of functions for the computer system beeing designed. Topics discussed in this paper are: Functional characteristics of Electric Power Substation, Functional organization of an Integrated System, Distribution of computer system architecture, Allocation of functions to elements of a distributed microprocessor-based computer system. Five different approaches for distribution of architecture and allocation of functions are proposed as a result of the analysis. A brief discussion of advantages and disadvantages for each of the approaches is outlined having in mind real time digital control application enviroment related to control and protection of Electric Power Substations.