The article presents main results of a comprehensive study of the command, control, communications and computer systems for the Bulgarian Ministry of Defense. It outlines current and planed C4 system capabilities of the Bulgarian armed forces. Recommendations for modernizing C4I systems to achieve requirements for NATO interoperability and standards, as well as priority projects are briefly described. Finally, the authors present roles and functions of organizational structures in the process of system development, accounting for the newly established C4I systems life cycle model.