While mobile learning (m-learning) has considerable potential, most of previous strategies for developing this new approach to education were analysed using the knowledge, experience and judgement of individuals, with the support of statistical software. Although these methods provide systematic steps for the implementation of m-learning strategies, they do not consider the correlations among the key success factors. This study aims to develop a decision support system for m-learning, and design m-learning activities that combine lessons in Chinese rhetoric with an outdoor learning activity at the National University of Tainan, in Taiwan. To verify the feasibility and value of the proposed decision support system for m-learning, the fuzzy analytic hierarchy process was used to analyse the three types of participants in this case study--college students, system developers and instructors from related fields. The evaluation indexes of the success factors of m-learning were used to obtain the opinions of each participant. The relative weight of each evaluation index was calculated, and the entire weight system of the indexes was established, which can then be used as a strategic tool for m-learning development.