4. Concluding remarks

Here, we have followed the situations of expertise that engineers might face, and to this end we have built an onion peel analysis model, which seeks to bring a little order to a very complex and evolving universe, even if it is already a long evolution (Denis Duclos described in 1989 "the intrusion of the unpredictable into the engineer's function" ). In this sense, it's an artifact: problems rarely present themselves according to these patterns. But it is the role of an artifact to propose a configuration of reality that enables us to think about it.

Starting with...