A top-down change process for rationalization of post distribution did not achieve the calculated productivity gains. Ergonomist researchers at Linköping University were consulted and in order to train management and postmen to develop a HTO-thinking, a number of learning laboratories were arranged by the research team. Using a model of Porras & Robertson (1992), 25 postal participants judged how each of the suggested improvement measures separately, explicitly or implicitly affected the work setting according to the model and thereby the outcome of the production system including the wellbeing of 15 000 postmen in a highly complex and intertwined way.