an extremely high - speed , very stable system and a method for concurrent computing between heterogeneous simulators are shown , in which heterogeneous simulators for analyzing a complicated physical phenomenon are coupled based on a coupled equation thereby to obviate the disadvantages of the conventional noncoupled and coupled methods . a numerical calculation unit includes a calculation control unit equipped with an agent function having a heterogeneous coupling variational equation calculation unit , a convergence decision unit and a search vector setting unit . a parameter and a variable are supplied from the heterogeneous coupling variational equation calculation unit into and out of a simulator a , a simulator b and a heterogeneous coupled equation thereby to form the heterogeneous coupling variational equation 1 and thus to determine a globally consistent solution . with this configuration , a globally consistent solution can be obtained automatically simply by setting a heterogeneous coupled equation , and therefore the analysis and design efforts of an operator can be very effectively supported in analyzing complicated physical phenomena in all the fields of advanced science and technologies .