Abstract: Guidances are provided for database retrieval in a numerical simulation system. A user can execute numerical simulation without knowledge of mathematical and numerical techniques. A physical model is generated using information of a region shape, material name, physical phenomenon name, boundary condition name, and the like, respectively inputted by a user. A mathematical model generating step calculates physical characteristic values from the physical model, and in accordance with the physical characteristic values, retrieves proper equations from an equation database. A calculation model generating step detects mathematical characteristic values from the equations to retrieve proper numerical algorithms for solving the equations from an algorithm database. A simulation information generating step retrieves from a package database a simulation package for solving the given physical problem by using the selected algorithms, and generates simulation information for the retrieved package.