Zaid Alabaddi, Haitham Alali, Arwa Rahahleh, Khaled Abdrabbo, The Relative Importance of the Critical Success Factors of Enterprise Resource Planning System (ERP) in Jordanian Pharmaceutical Companies, Journal of Engineering and Applied Sciences, Volume 14,Issue 17, 2019, Pages 6465-6473, ISSN 1816-949x, jeasci.2019.6465.6473, (https://makhillpublications.co/view-article.php?doi=jeasci.2019.6465.6473) Abstract: This study aims through a theoretical framework to identify the critical factors that might help in the successful implementation of Enterprise Resource Planning systems (ERP) by covering the most important aspects of the success of implementing ERP systems. Many previous studies have identified many factors that help in the success of ERP systems. This study summarizes these factors and identifies the most frequently recurring factors by reviewing previous studies and composing a table showing the recurrence of these factors. Then surveying managers, heads of department and employees of IT departments in Jordanian companies for the production of human medicines for the relevancy and the importance of the extracted factors. About 15 Jordanian companies that produce medications were surveyed. This study shows that the following factors namely (team competencies and skills, minimal customization, top management support user training and education, project management, communication between sectors, teamwork and composition and skills, clear goals and objectives, business process reengineering, organizational change management user involvement and package selection) are the most important in the success of implementing enterprise resource planning systems. Keywords: Enterprise resource planning system;critical success factors;Jordan;pharmaceutical manufacturing;medicines;surveying