made in correspondence with the previously defined function class step 203 as a result the figure format is added to the above described display class next a designation is made of a display slot of the user figure by the operator step 204 then the display slot definition format is added to the above explained display class subsequently the animation program is defined by the object oriented program and is set to the function class and the display class step 205 in setting of the animation program the method definition to initiate the animation is first set to the above explained function class step 206 then the method for the animation is defined with using the above described display slot and is set to the above mentioned display class step 207 next a model input by an instance is performed with employment of the applicable graphic editor the model input is carried out by drawing a figure indicative of the function class on the screen by the operator step 209 as a consequence an instance of a function class corresponding to the instance of the display class is produced upon completion of the model to be designed a simulation is carried out step 210 the simulation is performed by executing the method of the function class step 211 the result of this simulation is represented by executing the animation program step 212 more specifically the animation program is executed as follows first the animation initiating method is executed step 213 and the animation method is initiated and also executed step 214 the display slot is updated by executing the animation method step 215 as a result the figure is modified in.