  In Concurrent engineering, design solutions are not only produced by
individuals specialized in a given field. Due to the team nature of the design
activity, solutions are negotiated. Our objective is to analyse the
argumentation processes leading to these negotiated solutions. These processes
take place in the meetings which group together specialists with a co-design
aim. We conducted cognitive ergonomics research work during the definition
phase of an aeronautical design project in which the participants work in
Concurrent Engineering. We recorded, retranscribed and analysed 7
multi-speciality meetings. These meetings were organised, as needed, to assess
the integration of the solutions of each speciality into a global solution. We
found that there are three main design proposal assessment modes which can be
combined in these meetings: (a) analytical assessment mode, (b) comparative
assessment mode (c) analogical assessment mode. Within these assessment modes,
different types of arguments are used. Furthermore we found a typical temporal
negotiation process.
