Transdisciplinarity is considered an appropriate approach in supporting transitions of complex socio-technical systems as such transitions demand highly contextualized real world knowledge and valuations. This holds especially true for the problem identification and structuring (initial) phase of a transition project, which aims at supporting goal formation based on a sound understanding and representation of the system's current state and its dynamics. Throughout this phase, it is important that all relevant perspectives in terms of expertise and interests are considered and adequately fed into a process of knowledge integration. This paper presents in its first part the structuring for complex transitions (SCT) procedure aiming at this requirement. The procedure has been specifically designed for problem structuring in socio-technical systems in the initial phase of a transition project. The results of the procedure provide sound inputs for the next project phases and the transition methods applied therein, but can themselves already be used as fruitful orientations in strategy development. The second part of the paper briefly outlines the application of the SCT procedure to Swiss waste management. This application involved 48 participants who reached consensus on relevant impact factors and developed a shared vision for managing a complex transition process in the area of waste management. The approach is marked by high feasibility and socially robust results.