Analysing work in terms of activity is a paradigm which founds numerous studies in both the human and social sciences, and in engineering science. In this article, we discuss how activity analysis has been affected by the technological, social and organizational changes seen in the world of work over the past 50 years. We analyse activity from a psychological point of view, as the product of a coupling between a task (which provides external determinants), and a subject (who provides internal determinants). In the first section, we discuss the consequences of some factors that modify the task. We begin with the use of information and communication technology (ICT) in business. Next, we argue that it is becoming harder to describe the team, as the circle of protagonists in the workplace has expanded. Finally, we underline that the coupling between the task and the subject is weakened, due to its extension to non-work situations. In the second section, we discuss the consequences of transformation of the subject’s internal conditions, as a function of three factors; the integration of mental, psychosocial and social dimensions into the analysis of work; the growing hybridization of human and artificial agents; and the exploitation of interpersonal relationships by the corporate social network.