Optimal Implementation of quality management system ISO 9001:2008in a private higher education institution should improve the quality of the performance which in turn can raise the competitiveness and sustainability of the higher education institutions. This study analyzes implementation of ISO 9001:2008 quality management systems at the University X Bandung that classified based on the level of interest and performance in their respective quadrants using Importance- Performance Analysis (IPA Method). After the Cartesian diagram have been outlined, be obtained that Focus on the Customer, Leadership, and Continual Improvement Process Principles at University X are very satisfied. The Involvement of Personnel Principle and The Making Decisions based on Facts Principle are included to the repairing main priority. The Mutually Beneficial Relationships with Suppliers Principle is defined as low priority. The Process Approach Principle and The System Approach to Management Principle are excessive categories. Furthermore, this research is continuing with identify the causes of repaired principles main priority using fishbone diagram and found that the 3rdprinciple is low was caused by the institutional behavior is not support to personnel involvement, in addition to the 7thprinciple is still low too, was caused by decision maker skill is still not good. Finally, the solution alternatives from that causes would be found using tree diagram.