The text presents a point of view on the ergonomics of customer-operat
or relationships, grounded on the authors' experiences of actual inter
ventions in that type of task. After having specified the field covere
d by the ergonomics of services, four different approaches are develop
ed, corresponding to four different status given to the customer in ta
sk fulfilment, namely : the absent customer, the customer as a factor
of work conditions, the customer as the object of the work, and the cu
stomer as a partner in a cooperative task. Following this over-view, t
he next section considers different aspects of cooperation in customer
-operator relationships: the principles underlying the interactions, t
he cooperative definition of the task, the assessment of task fulfilme
nt and the role of dialogue modelling. The last section considers the
consequences of this approach for the ergonomic analysis of customer-o
perator relationships. As far as the operator's activity is concerned,
the need for taking into account the specific constraints caused by t
he interactions with the client is stressed. As far as clients are con
cerned particular attention should be paid to their activity and to to
ols that would make them better cooperators. Finally, the text advocat
es the necessity of situating customer-operator interactions within th
eir organizational context and the need for ergonomic studies that wou
ld encompass the emotional aspects of these interactions.