This thesis is situated in the domain of method engineering and more specifically in situational method engineering. It proposes a construction technique of analysis methods, called Extension, allowing to adapt a method to the project at hand. The proposed approach focuses on three following techniques : A knowledge representation based on specific patterns. They are described by different description and manipulation languages. A patterns organisation using maps. Maps are executable processes allowing to extend an object oriented method to a specific application domain. They guarantee the method coherency management by taking into account the precedence constraints associated to each pattern. A patterns conception with meta-patterns. These specific patterns are generics and guide the maps construction. They are generated by the inventory of all the possible strategies that may be proposed by a map. The knowledge provided by each of these strategies is encapsulated in a corresponding meta-pattern. This approach provides a guidance process, on one hand for the patterns execution (map) and on the other hand for the patterns construction (meta-pattern).
