ABSTRACT
Quantitative risk assessment relies on models. Model building is one of the rarer skills in the world of risk assessment. A model-building process comprising 13 steps is offered. The steps are: (1) get the question right; (2) know the uses of your model; (3) build a conceptual model; (4) specify the model; (5) build a computational model; (6) verify the model; (7) validate the model; (8) design simulation experiments; (9) make production runs; (10) analyze simulation results; (11) organize and present results; (12) answer the question; and (13) document the model and results. Model building requires technical skills and craft skills. Building models in a spreadsheet environment is open to more people than code-based models are. Powell and Baker's modeling heuristics are summarized and followed by a review of a number of helpful ideas for building spreadsheet models.
