In a conventional quantitative plan simulation, it is practically impossible to prepare a spreadsheet-type data input template applicable to all types of plans. Thus, a quantitative plan simulation system is required to handle a plurality of spreadsheets containing variously-formatted data. Therefore, the present invention provides a simulation system, a simulation method and a simulation program which are configured to extract a numerical value, a mathematical formula or other kinds of data necessary for a quantitative plan simulation, based on a relevancy among numerical values and mathematical formulas or other kinds of data in a spreadsheet, and perform the quantitative plan simulation based on the extracted numerical values and mathematical formulas.