  We present an empirical study aimed at analysing the use of viewpoints in an
industrial Concurrent Engineering context. Our focus is on the viewpoints
expressed in the argumentative process taking place in evaluation meetings. Our
results show that arguments enabling a viewpoint or proposal to be defended are
often characterized by the use of constraints. Firstly, we show that, even if
some constraints are apparently identically used by the different specialists
involved in meetings, various meanings and weightings are associated with these
constraints by these different specialists. Secondly, we show that the implicit
or explicit nature of constraints depends on several interlocutive factors.
Thirdly, we show that an argument often covers not only one constraint but a
network of constraints. The type of combination reflects viewpoints which have
specific status in the meeting. Then, we will propose a first model of the
dynamics of viewpoints confrontation/integration.
