Indonesia as one of the favorite vacation destinations of domestic and foreign travelers made the value of investment in the tourism industry continued to grow significantly. This was created more Online Travel Agent business in recent years. However, it made a lot of business travel and Umrah travel in Indonesia is threatened with bankruptcy, after the online travel business activity is rampant in enterprise business market ticket sales and travel tours. The case study of this research was different from the Online Travel Agent business in general because it worked in real-time using flight tickets and hotel rooms sales data. Data mining, extraction of hidden predictive information from large databases, was a powerful technology with great potential to help companies focus on the most important information in their data warehouse. By using the method of classification in data mining, the objectives of this paper was able to create predictive models from flight tickets and hotel rooms sales data using the decision tree classification approach. The result of this paper is beneficial for business that can be used as basic algorithm for programming in Online Travel Agent recommendation feature.
Keywords: Data Mining; Decision Tree; Classification; CHAID; C5.0.