Group model building supports team decision making by guiding participants through a process of joint model construction. Guided by a facilitator, team members first generate a list of problem elements and then iteratively build the model. The model is visualised as a word-and-arrow diagram in front of the team. Each time a team member suggests to add a new element to the model, the facilitator draws the proposed relation and then checks for the team’s agreement. Group model building uses a particular type of models: system dynamics. System dynamics originated as a quantitative, formal modelling approach and has since developed a strand of qualitative, conceptual modelling as well. Group model building has been found to improve communication between members of a decision-making team, enabling them to share and integrate ideas and develop new insights. Team members achieve consensus on what the issue is about and commitment to proposed actions.