The purpose of this article is to describe the use of the Concerns Based Adoption Model (Hall & Hord, 2006) as a conceptual lens and practical methodology for professional development program assessment in the vocational education and training (VET) sector. In this sequential mixed-methods study, findings from the first two phases (two of five) of data collection and analysis are used as examples to profile the journeys of professional change experienced by 27 VET teachers involved in a four-year systemic-change professional-development initiative designed to extend and refine their pedagogical practice. The examples support the view that a Concerns Based Adoption Model provides an effective framework for better understanding teachers' professional change in a VET context. The conceptual and practical usefulness of this approach is discussed in terms of its implications for the future design, implementation and assessment of professional development initiatives. (Contains 6 tables.)