In this study, we applied process mining techniques to discover outpatient care process and confirmed that process mining techniques can be useful even in a healthcare environment where a variety of devices and systems are used. In particular, unlike previous studies that did not compare the machine-driven process model with an expert-driven processmodel, we tested whether there is a recognizable difference in practices within hospitals by analyzing the machine-driven process and comparing it to the expert driven process model. Proper application of the process mining technique only pertains to the log data stored in a system, which limits the application of the technique for processes that do not record the time duration, such as treatment activity. Thus, future studies should determine which data to utilize in such cases.