This article deals with the conditions that allow supporting professional itineraries in terms of health and competencies. Ergonomics is led to specify how a diachronic dimension can be included in its analyses and, as a prerequisite, to formalize its conception of time. Taking activity into account leads to considering a professional itinerary not as a simple succession of positions, but also as the length of time lived and experienced. Itineraries are shaped by a combination of multiple temporalities meeting at the crossroads of social times – which incorporate the models of development of institutions and persons – and individual, biological and psychological times. Such an outlook induces a pluralistic conception of time, in which it is both endured and constructed, quantitative and qualitative, individual and collective. A conception of time that is also a social and psychological construct, empowering individuals and groups to produce time.
Contemporary forms of labor organization bear the stamp of the flexibilization of the means of production and the workforce. Based on instant performance, they break with the past or the value of experience, as well as with the future, that workers see as a perpetual adjustment to the present. Presentism prevents elaborating a professional itinerary that preserves the continuity between past, present and future. Worker collectives may interfere with that conception by producing rules to guarantee continuity. An activity that allows people to build up a constructive itinerary is thus one that allows them to make history, i.e. an itinerary that circulates between the field of experience and the horizon of expectations. By integrating multiple times, ergonomic job analysis is part of a project for temporal ecology whereby social and individual times are mutually supportive. Our analysis seeks to reveal those multiple times, to include them in the debate and make the past and future accessible in the activity.