This paper proposes an active mining process for improvement of quality of clinical process by using service logs in a hospital information system. First, datasets of temporal change of the number of orders are extracted from service logs stored in hospital information system. Then, since datsets of temporal change can be viewed as time-series of a statistic, clustering can be applied to the data. By using the groups obtained, datasets of command sequences are extracted from the logs and sequence mining process is applied. The results of sequence mining are interpreted with the results of clustering and hypothesis will be generated. The results show that the method improved the clinical process and waiting time in outpatient clinic.