Late-binding and substitutability offered by the service-oriented approach improve adaptability but increase the need for fast and efficient algorithms to select services. In this paper, we proposed to use the Formal Concept Analysis (FCA) approach as a classification tool to select services at runtime, according to user specifications. We propose to classify existing services and generate a decision tree to help user select the most appropriate service(s). One of advantages of using FCA is the ability to select without additional cost an equivalent service in the case of a service must be replaced at runtime. Our approach have been implemented and validated on pervasive use cases within a European collaborative project.