This paper analyses relations to productivity in several employee categories in a French firm: the telephone operator that had a monopoly until the end of the 1990s. The relations that different actors in the firm (managers, supervisors, operators) have with productivity vary, depending on their level in the hierarchy and on the inquiry centre. The author draws on a survey consisting of interviews, observation and consultation of archived documents, to show differences between local centres and their impact on definitions of productivity. Her analysis then reveals the social forms of definitions of productivity in two very different centres.