International Journal of Academic Research in Business and Social Sciences February 2014, Vol. 4, No. 2 ISSN: 2222-6990 440 IJARBSS – Impact Factor: 0.305 (Allocated by Global Impact Factor, Australia) www.hrmars.com Identifying and Ranking Factors affecting the Successful Implementation of ERP by using Fuzzy Delphi and Fuzzy Analytical Hierarchy Process Maryam Nayebzadeh Department of Computer Engineering, Islamic Azad University, Yazd Branch, Yazd, Iran Email: m.nayebzadeh@gmail.com Fatemeh Saadatjoo Department of Computer Engineering, Science and Art University,Yazd Branch, Yazd, Iran Email: fatemehsaadatjoo@gmail.com Hasan Dehghan Dehnavi Department of Management, Islamic Azad University, YazdBranch, Yazd, Iran Email: denavy2000@yahoo.com DOI: 10.6007/IJARBSS/v4-i2/666 URL: http://dx.doi.org/10.6007/IJARBSS/v4-i2/666 Abstract The enterprise resource planning system is business process management software used to integrate the existing organizational information and used for the concentrated control and management of all facets of the operations. To successfully implement the enterprise resource planning systems, it seems necessary to identify and pay attention to the effective factors of its implementation. This study aims to identify and rank these factors by using fuzzy Delphi and fuzzy analytic hierarchy process. Based on the experts’ opinions, the effective factors in terms of the experts’ opinions are identified in the first step. These factors are then ranked based on the opinions of the experts of the tile and ceramic industry in Yazd. Eight main factors are identified and their priorities are the users, experts, organization, software, technical- technologies, cultural, managerial and economical dimensions, respectively. Keywords: Enterprise Resource Planning, Fuzzy Delphi, Fuzzy Hierarchy Process. Jel Classification: M15 Introduction In the today’s competitive world, the planning systems and the integrated databases constitute the essential components of the large enterprises. This requirement increases as the enterprises become larger. Enterprise resource planning is one of the most comprehensive