Method for computer-aided simulation of a modular technical system, in particular a modular process installation, wherein a processor for a respective real module of the modular technical system is used a) to read in module-specific data of the real module and to take the module-specific data as a basis for generating a corresponding virtual module that comprises - a controller for controlling a module-specific process, which controller is present as a hardware project or as an emulation, and - at least one module-specific simulation model, which has associated model type information, for simulating the module-specific process, wherein the module-specific simulation model has a first interface by way of which cross-model variables of the module-specific simulation model are interchanged, and that is designed to replicate the module-specific process controlled by the controller, by means of the module-specific simulation model, and/or the controller of the real module, and b) to provide the virtual module as a data container for a computer-aided simulation of the modular technical system, wherein the virtual module is provided as an encapsulated data container, wherein c) predefined configuration information of the modular technical system is taken as a basis for selecting real modules of the technical system, providing corresponding virtual modules for the selected real modules and reading said virtual modules into a simulation environment, and d) the virtual modules are coupled to one another in the simulation environment on the basis of the configuration information and a computer-aided simulation of the modular technical system is executed, wherein predefined simulation type information for each virtual module is taken as a basis for replicating a module-specific process controlled by the respective controller, by means of a respective module-specific simulation model, the associated model type information of which complies with the simulation type information, and/or the controller of a respective module-specific process. a) to read in module-specific data of the real module and to take the module-specific data as a basis for generating a corresponding virtual module that comprises - a controller for controlling a module-specific process, which controller is present as a hardware project or as an emulation, and - at least one module-specific simulation model, which has associated model type information, for simulating the module-specific process, wherein the module-specific simulation model has a first interface by way of which cross-model variables of the module-specific simulation model are interchanged, and that is designed to replicate the module-specific process controlled by the controller, by means of the module-specific simulation model, and/or the controller of the real module, and - a controller for controlling a module-specific process, which controller is present as a hardware project or as an emulation, and - at least one module-specific simulation model, which has associated model type information, for simulating the module-specific process, wherein the module-specific simulation model has a first interface by way of which cross-model variables of the module-specific simulation model are interchanged, b) to provide the virtual module as a data container for a computer-aided simulation of the modular technical system, wherein the virtual module is provided as an encapsulated data container, wherein c) predefined configuration information of the modular technical system is taken as a basis for selecting real modules of the technical system, providing corresponding virtual modules for the selected real modules and reading said virtual modules into a simulation environment, and d) the virtual modules are coupled to one another in the simulation environment on the basis of the configuration information and a computer-aided simulation of the modular technical system is executed, wherein predefined simulation type information for each virtual module is taken as a basis for replicating a module-specific process controlled by the respective controller, by means of a respective module-specific simulation model, the associated model type information of which complies with the simulation type information, and/or the controller of a respective module-specific process.