This paper focuses on the management of alternatives machining operations, essentially from an access orientation point of view, during computer aided process planning of aeronautical parts. Characteristics of these parts entail to consider a larger amount of alternative machining operations for one single feature than considered in usual approaches. Using visibility map concept, taxonomy of “machining direction sets” is proposed to manage these alternatives. Then, procedure to handle theses alternatives sets through a step of the set-up planning stage is suggested.