Based on a partnership between IMT Atlantique and the French company Lumiplan, this work is part of a process of strengthening the Heurès software currently offered by Lumiplan to public transport operators to support their bus and driver scheduling operations. This work addresses the frequency setting problem which aims at defining the frequencies of the bus lines of a network for different time periods of a day. This operation complements a study on line planning with more accurate estimations of the demand, necessary bus types and passengers behaviors. In this paper, the operator’s xploitation costs are minimized while respecting service-levels constraints, based on the predictions of the path choice made by the passengers. The problem is solved by an easily implementable process and a case study based on a real network is presented to show the efficiency of our method.