1. A system configured to generate a customized application data structure for modeling physical systems, the system comprising: one or more processors, one or more user input devices, optionally a display device, and one or more memory devices, wherein the one or more processors are adapted, during use, to embed a pre-determined or selected multiphysics model data structure in an application data structure, wherein the multiphysics model data structure comprises a representation of one or more models of physical systems, each model of a physical system representing physical phenomena and/or physical processes, wherein the multiphysics model data structure comprises data representing at least one modeling operation determining how to model or simulate the one or more models of physical systems, add data representing one or more application features to the application data structure, where each application feature comprises one or more of (i) first data representing at least one form feature, and/or (ii) second data representing at least one action feature, wherein a form feature comprises data specifying input data and/or output data and/or presentation format of input and/or output data, and wherein an action feature comprises data specifying a sequence of operations to be carried out, when executing the application data structure, and wherein at least one of the sequence of operations to be carried out comprises the at least one modeling operation, and wherein at least one of the sequence of operations to be carried out comprises an operation providing data for generating at least one geometry of at least a part of the one or more models of physical systems, whereby a customized application data structure is generated providing, when executed, a customized modeling of the physical systems using the at least one modeling operation, the at least one geometry of at least a part of the one or more models of physical systems, and at least one of the one or more application features.