The distinction between the developments of health economics decision models provides a mechanism to synthesise evidence from a range of different sources to inform policy debates and public health guidance decisions. In this session, exemplified by a discussion of the development of the Sheffield Alcohol Policy Model, we will discuss some of the main generic steps in model development. These iterative steps include a clear understanding of the scope of the decision-making and the policy options to be considered, processes for searching and reviewing existing relevant evidence, identifying analysing and synthesising existing available data sets and developing a detailed enough model to enable policy analysis. Key features of the Sheffield alcohol policy model include the use of individual level survey data on risk factors including levels of drinking and purchasing patterns, evidence on the association between risk factors and harms including 47 different clinical conditions defined by ICD10, levels of crime, work absence and unemployment, and evidence on the valuation of harms including quality of life effects due to health and crime and financial effects on the healthcare, justice and workplace or systems. We will finish with a brief consideration of how these generic issues are also reflected in a second project concerning public health guidance around prevention of diabetes.