For more than 20 years, French animal scientists studying livestock farming systems have been interested in the question of work organization in livestock farms and they developed the Work Assessment method to characterize and assess it. Widely used since then in France, and in other countries too, this method quantifies work related to the management of herds and land areas, and evaluates the farmer's room for maneuver in terms of time to carry out other activities on the farm and to have free time. The purpose of this paper is to show the interest of the Work Assessment method, illustrating with examples from the application of the method in 6 countries in the North and South (France, Belgium, Vietnam, Morocco, Uruguay and Brazil), how it characterizes and assesses work organization; how it identifies the main determinants of organization, produces references in working times by major types of production system and provides analyses for the advice and guidance of livestock farmers. By identifying forms of work organization, the method shows that the farmers' strategies are not only technical and economic but also integrate parameters relative to work (productivity, working together, freeing up time for other activities, including private activities…). Its use in very different contexts in France where it was developed, underlines its ability to adapt to different livestock farming contexts, and to different contexts of use too, such as research and advice.