Crystal Ball works with spreadsheet models, specifically Microsoft Excel spreadsheet models. the spreadsheet might already contain a model, depending on what type of information you have in the spreadsheet and how you use it.
If you only use spreadsheets to hold data — sales data, inventory data, account data, and so on — then you do not have a model. Even if you have formulas that total or subtotal the data, you might not have a model that is useful for simulation.
A model is a spreadsheet that has moved from being a data organizer to an analysis tool. A model represents the relationships between input and output variables using a combination of functions, formulas, and data. As you add more cells to the model, the spreadsheet begins to portray the behavior of a real-world system or situation.