Instructional planning is acknowledged as an important factor influencing the quality of classroom teaching. DigUp is a Research and Innovation in the Public Sector project which has received funding from the Research Council of Norway. Using a design-based research methodology, the objectives of DigUp are to design, trial, optimise and disseminate an online, didactic planning tool for teachers and to investigate how teachers use and experience the digital planning tool. The innovation part of the project has been developed in a close collaboration between researchers and practitioners in primary and lower secondary school. It applies perspectives from backward design, inquiry-based learning and disciplinary literacy. A combination of quantitative and qualitative data has been collected, providing the empirical basis for a research-based online tool that supports teachers in their planning. This protocol paper presents the background, design process and future research plan for the project.