To build the models, modelers often rely heavily on previous analysis and modeling work. They may study existing data models and databases, refer to published standards, and incorporate any data requirements. After studying these inputs, they start building the model. Modeling is a very iterative process (this Figure). Modelers draft the model, and then return to business professionals and business analysts to clarify terms and business rules. They then update the model and ask more questions (Hoberman, 2014).