This paper presents an overview of ongoing research from within the Tailorcrete research project into the development of CAD tools for the design and realization of 'non-standard' concrete structures. The focus is on concrete formwork, a significant factor affecting cost, logistics and aesthetics. With a process spanning a broad range of expertise, collaboration through an effective digital workflow is vital to the successful execution of such structures. As a concept for this workflow, a working model of a Design System is described and its development discussed. This focuses on three aspects: (1) the identification of key Use-Cases, (2) the definition of Formwork Systems, and (3) the definition of communication between software elements to provide relevant means of collaboration for expert users. An implementation as a package of software prototypes is also briefly presented. This includes a Base Framework, tools targeting Use-Cases and components relating to specific formwork systems.