This paper aims to provide some support for the widespread claim that agroecological transition entails a wide variety of changes for the farmer. To that end, it focuses on farmers' work systems, as evidenced through several subsystems: biological and technical, socioeconomic , family, and related to the farmers' characteristics. Two case studies are used to illustrate how farmers' concerns, which are drivers of change, are constructed at the interface of these subsystems. For each case study, the paper focuses on a single concern described by the farmer during a workshop by means of the Chronicle of Change method (Chizallet et al., 2020). This makes it possible to dissect the subsystems of work to which the farmer refers in relation to a concern, to show how these references differ, depending on whether the farmer refers to them in a state of transition, and when he adopts a systemic approach to his concern. Beyond this paper, this research work is continuing with support for farmers' agroecological transition with regard to tools and methods in a systemic approach. It is thus shedding light on the transition from a work point of view and not only from a technical point of view.