A significant gap between the standards in SLA (Service Level Agreement) and the reality of service. Customer complaints indicate a delay in response time that does not meet the SLA targets. Customers tend to lose trust in the reliability of the service amid intense industry competition. Given the crucial role of the e-ticket system in maintaining satisfaction and loyalty, as well as indications of SLA fulfillment failures, a comprehensive evaluation of the system's performance becomes urgent. This research focuses on the analysis of the gap between SLA standards and implementation at Telkom Temanggung, as well as revealing the root causes that affect response speed and customer loyalty. This study adopts a quantitative approach with a descriptive evaluative method and the PIECES model to assess and analyze numerical data objectively related to the performance of the e-ticket system and customer satisfaction at Telkom Temanggung. The results of this study indicate that the Telkom Temanggung e-ticket system is considered effective with an average satisfaction effectiveness score of 3.78; however, the dissatisfaction analysis ranges from 18% to 28%. The Information and Economy aspects recorded the highest ineffectiveness percentage (28.8%), with main issues such as complaints that were not recorded/delivered and customer doubts regarding the economic aspects of the system. The Performance aspect (18.6% ineffective) is still constrained by the application transition, which causes longer response times. This indicates a gap between expectations and the reality of service that could potentially affect customer loyalty in the future.