We, as teams external to our clients, usually don't have any organisational power. Although simply doing our work, we are nonetheless implicitly changing the culture of the client company. We don't take effect by position and managerial authority but by doing, through our roles and by being who we are. We value the meaning of instruments and procedures and we are looking at cultural change not only as a result by accident but as a desirable goal. Let's have a look on three role-models in the context of cultural change stimulated by external staff.