The issue of modularising vocational education and training (VET) systems has been the subject of heated debate in many European countries. In particular, in Scotland the use of modules within the curriculum has been seen as either restrictive or liberating depending upon the theoretical stance taken. At a more pragmatic level modularisation of VET has been regarded as one facet of a broader strategy to modernise training systems. Indeed, a strategy that has resulted in significant changes at the system level in VET, with a consequent impact at the institutional and practitioner levels. These discussions on modularisation have been on going in Scotland since the mid-1980s and are still of relevance today. However, rather interestingly this initial enthusiasm in Scotland for modular approaches has waned slightly and been replaced by a degree of scepticism. The work of Professor David Raffe and his colleagues at Edinburgh University has been instrumental in shaping the debate about modularisation. In particular, the conceptual contribution based upon the notion of "institutional and intrinsic logic" and "institutional diversity" has been very helpful. David acted as an advisor to our modularisation project with CEDEFOP and repeatedly reminded us of the need to collect data on implementation studies, with a particular comparative focus. This article will do just that, building upon a distinctive theoretical framework we will explore how modularisation has impacted on the work-based Scottish VET curriculum. Fortunately, we have substantial data on this based upon the example of a "mature" VET system that has a long history of using modular based curriculum. Our findings will illustrate how modular structures can work towards both an expansive and restrictive notion of learning and assessment.