Representations are at work in IT technology. As plans of and for work, they enable cooperation, coordination, accountability and control, which have to be balanced off against each other. The article describes a standard developed for electronic health records (EHR) and the results of a test of a prototype built on that standard at a department of internal medicine in 2004. It is argued that the prototype did not support clinical work, which is attributed to the model of work embedded in the standard, called Basic Structure for EHR (BEHR). The article concludes by calling for critical conceptualizations of the relations between representation, work and knowledge production.