This is a step-by-step guide created by DESNZ and HM Treasury for analysts and policymakers who wish to apply Multi-Criteria Decision Analysis (MCDA) in policy development as per HM Treasury's Green Book guidelines. It should be read as a supplement to the Green Book.

It covers:

• when to use MCDA in options appraisal
• the general approach to follow
• the main points to consider
• common pitfalls to be aware of

MCDA is a technique that helps decision-makers to make rational choices between alternative options when these are required to achieve multiple specific objectives. It is particularly effective when there is a mix of qualitative and quantitative criteria not directly comparable against each another and when the perspectives of multiple stakeholders may need to be considered.

The Green Book recommends using MCDA to support identification and ranking of choices during the longlist appraisal stage when the standard process is insufficient to construct a preferred way forward to take to shortlist stage. By including the findings from the MCDA exercise in the final business case, analysts would then have a transparent record of the evidence and assumptions used to derive the shortlist, and reviewers would be assured that all options have been properly and fairly considered against policy objectives.