Competition today has been perceived for all either national or multinational companies. Company performance evaluation get more stringent to afford offset competition rules. Information system is one of tools supporting the course of business process company. Evaluation of information system will give impact towards of business process also. PT Telkom is one of companies that applying an integrated information system for supporting its business process performance. By using the Method of Architecture of Integrated Information System (ARIS), business process of information system of PT Telkom especially in division of IS Center modeled to do more analysis of business process. In determining improvement, analysis of delay causes is applied on ticket handling process either change ticket or incident ticket using Root Cause Analysis (RCA). From the roots of the causes that generated could be analyzed further to determine improvement scenario which is possible. The scenarios of improvement was simulated for ensuring its contributions against time process of ticket handling and then Benefit/Cost Rati (BCR) could be applied for ensuring the artio of benefit for the process improvement with cost of improvement. The result of the most feasible improvements are determinate fix due date in change ticket handling and application of alarm system in incident ticket handling.