A mechanism for graphically performing structural templatization in a graphical model is discussed. A model component with a defined interface is designated as an “interface component” and includes at least one external interface port and one or more internal ports. An instance of the interface component is instantiated in a graphical model and exposes the external interface port. A user also instantiates in the graphical model an instance of a component that is designated as an “implementation component” that includes model functional content and which exposes an implementation port. The user connects the exposed interface port and implementation port and the internal port information from the interface component programmatically merges with the content of the implementation component. The model designer is thus able to concentrate on separately providing interface and content information during the design of the graphical model.