All addiction treatment centres face the challenge of allocating resources across budget areas to obtain best value for money. This requires a clear sense of priorities that balance costs, risks and bene ts, where bene ts can be any mixture of nancial and non- nancial value. But how can monetary costs, uncertainty about the future and multiple, con icting objectives be ‘balanced’ when they are all very di erent? The answer is to be found in multi-criteria decision analysis (MCDA), a theoretically sound, highly practical, and well-tested approach that uses both data and human judgement to carry out this balancing act. After a brief introduction to the principles of MCDA, Professor Larry Phillips will facilitate a small group of addiction experts in a decision conference to develop a prioritisation for allocating resources across budget areas of a hypothetical treatment centre. The session will end with a discussion of how this process could be implemented.