Researchers from National Armed Forces (NAF) Republic of Latvia in cooperation with researchers from Riga Technical university (RTU) based on analysis of NATO normative base and open source information of clothing and individual protection systems, have established massif of functions containing functions of protection, functions influent on combat ability and technical economic functions describing quality of the Soldier Individual Protection System. Researchers develop methodological approach of identifying priority group of functions. The basis of this approach is military expert evaluation with aprior ranking of functions. The results of aprior ranking with definition of priority functions can be used by government officials as a scientific basis in defining direction of further Soldier Individual Protection System improvement and optimization projects as well as set up requirements for the multi protection and multi layer type of the individual protection systems.