Hospital managers search ways to streamline the process of outpatient’s service byoptimizing the use of resource involved in the process. One of the main objectives of hospitalmanagement is to reach the optimized utilization of human resource, medical equipments,treatment rooms as well as maximized customers’ demand. It is translated into a rational use ofresources and maximization of the customers’ satisfaction, who contributes to the enterprise’sdurability. Using simulation models, the hospital manager is enabled to assess utilization ofhuman resources involved in the process and, in effect, increases customers’ satisfaction. In thisstudy, a Thai hospital is taken to exhibit how the process of outpatient’s service, as a case, issimulated. AweSim®version3.0, a discrete event simulator, is employed to simulate this servicesystem. Design parameters are derived and adjusted to examine the effects. This paperdescribed research in a Thai hospitals’ outpatient process systems, focused on a study of how toorganize limited resources to gain reduction of overall service time as well as an increase ofcustomers’ satisfaction, and to provide a recommendation for a better service in outpatientprocess systems.