Selecting proper information system (IS) applications to implement may improve the effectiveness of the investment. The authore analyse the relationships among the properties of the enterprise, competitive priorities and the benefits obtained through the implementation of the IS applications. Based on the analysis a method to determine the implementation priorities of the applications is presented. Firstly, the initial priorities are determined by considering the effect of the enterprise properties on the benefits of the applications. Secondly, the priorities are modified by considering the competitive priorities. Finally, the actual form of implementation is proposed based on the analysis of competitive priorities.