Abstract Customer Satisfaction is an essential part that public service management must achieve in their services. KAI (Kereta Api Indonesia) management, as the civil service administrator, should make customer satisfaction as their top priority to ensure customer loyalty. The existence of this conditions requires the operator to measure some variable that would affect customer satisfaction to improve services. This journal will focus on the performance during the operation phase and its implications to KAI management. It is proposed to use Dynamic System modeling and simulation to explore the problem of user satisfaction.