Design and Validation of the Effective Size Model of Internet Audit Department

This study aims to provide design and validation of the effective size model of internal audit department in Iranian companies. The purpose of this research is an applied-developmental research that has been done by cross-sectional survey method. The statistical population of this study includes the partners and managers of the Iranian Association of certified public accountants and the employees of auditing firms. Sampling of managers was done in a non-probabilistic and purposeful manner and staff sampling was done by random sampling method. The data collection tool is a questionnaire. The validity of the questionnaire was confirmed by construct, convergent and divergent validity. The reliability of the questionnaire was also confirmed by two methods of calculating Cronbach's alpha and combined reliability. Structural-interpretive modeling method was used to design the initial model and partial least squares method was used to validate the designed model. Data analysis was performed with MicMac and Smart PLS software. The results show that "comprehensive internal audit plan" and "corporate governance structure" have the greatest impact on determining the effective size of the internal audit department. These elements affect the "internal audit methodology approach" and the "description of internal audit tasks". Similarly, "human resource management", "risk management" and "internal audit mission" affect the "quality of the audit committee". The quality of this committee affects the "value added of the internal audit" and leads to the determination of the "size of the internal audit".