Andy is interested in modelling the world, considering its alternative futures, and mitigating risks. In GENESIS and NeISS, Andy has worked on demographic models which represent individual people. He has developed two types. One type are traffic simulations that tick on a second step and track location on contemporary maps using 10 metre by 10 metre rasterisation. The model is contemporary and use OpenStreeMap for routing people from origins to destinations. The second type is more like a migration and natural change model which ticks on a daily time step. In this every individually represented person is assigned a usual residence. In a time step people may die, become pregnant, give birth and move. These models have been designed to scale to large populations and regions of study and to utilise large scale computational resources yet also run on the average desktop. The models are essentially bespoke Java programs.