The Pizzeria is an exercise in understanding and applying the GSDP to two organisational transitions that a pizzeria experiences in the course of time. The transition from the first to the second phase consists of adding the home delivery service. It implies a change in the essential model. This change appears to have interesting consequences for the allocation of authority: the performing of several C-act kinds has to be delegated, just for logistic reasons. Despite the huge differences between the second and the third phase in terms of implementation, their ontological models do not differ.