Explaining Root Definitions of Iran's System of Official Statistics by Soft System Methodology Approach

National programs of Iran’s five-year statistics for providing necessary requirements to improve Iran’s statistics status nationally and internationally are defining without having theoretical and applied definitions of official statistics, system of official statistics, and official authority of Iran’s system of statistics. This paper explains the Root definitions of Iran’s system of official statistics. This research is a qualitative one and based on research in Soft Operations and Soft System Methodology(SSM).Throughout the seven stages of this methodology, other approaches and methods for doing a qualitative research was used including content analysis, interpretive analysis, comparative studies, depth interviews with experts, and doing semistructured meetings with the experts of focus group and Consensus group. The expert interviewees were selected by using snowball sampling and reaching the volume of 40 persons. The findings resulted in presenting Root definitions of official statistics, system of official statistics and explaining the concept of authority of Iran's official system of statistics. Other outcomes of this research are counting official statistics in the world and determining the boundary between official statistics and specialized department statistics in Iran's system of official statistics.