Flexibility and stability seem at first glance to be opposites placing contradictory requirements on the vocational education and training system. Nevertheless, they are two important contextual conditions which need to be taken into account. The present article discusses this pair of opposites and the demands they create whilst also making reference to the function of the VET system and to the link between the education system, the world of work and the individual which is imparted via the notion of vocationalism. It also looks at them from an occupational biography development perspective. This approach allows the conflicting relationship between stability and flexibility to be substantiated as a basis for further development of the vocational education and training system. The perspectives for this are addressed in the final section by introducing the term “ambivalent functionality”.