Key point summary: When doctors treat patients good outcomes must be traded off against bad, taking into account the values of the individuals involved. In management the perceptions of the community as a whole determine the values. Decision analysis is a way to separate the treatments that add net value from those that do not, and to compare the relative value of beneficial treatments, on the assumption that it might not be possible to implement them all. Decision analysis is a powerful means of defending decisions taken, and can be applied to individuals and groups.