Hi Laurent,
""""""Can i ask you what was the way you proceed ?""""""""

For the model i posted, you can just select the entire model and run fillet .02.

Michael gave a good explanation. If you wanted to start doing "edge fillets", these will succeed too, but you have to pay attention to selecting "all the edges" that play into the surfaces in question. It can also eventually lead you into a corner where you are left with an edge that cant be calculated. Viacad is really good at doing these segmented edge fillets and completing a result.. If you want to start selecting several single edges and running various fillets in different areas, it will require more time spent. You will have left the push button fillet arena so to speak.