The idea, proposed in this work, is that who are introducing educational innovation in University teaching should focus more on the renewal of a curriculum more than in a single course's changes. University teaching innovation often focuses on the changes introduced within a single discipline through the adoption of some educational technologies or new teaching-learning-evaluation methods, keeping the focus only on the single discipline and not on the curriculum as a whole. With reference to the work of Ronald Harden about the eight roles of the university teacher, we underline the role of Curriculum developer and implementer. Six models are proposed to classify the introduction of innovative curricula. The different ways by which Problem Based Learning was introduced in university curricula are described as examples of the six models.