In recent years, a so called ‘transition system’ has become an established part of the overall vocational education system in Germany, enrolling those who have not accessed the dual-system or academic pathways. The expansion and stabilisation of this system underlines transition difficulties specific to the German context. With reference to a design-based research and development programme with 17 vocational schools, this paper describes the development of this sector and presents a set of school specific challenges emerging through this reform. Teachers at vocational schools and especially in the transition system are challenged to promote personalised learning and students’ individual competence development. The five basic problems of the transition system can be found in (1) clarifying how it can facilitate the integration of vocational orientation, (2) handling the large number of qualifications, (3) dealing with the dominant and overpowering dual system, (4) coping with the challenge of heterogeneous student groups and students with special needs, and (5) the necessity of personalised learning environments (cf. Kremer et al. 2012). All these aspects also lead to rising requirements for the teachers. For example, teachers will increasingly have to work in multi-professional teams – e.g. with qualified social education workers or even with psychologists.