Very often when a project was started for some time, a lot of model elements are created, and most of them are placed at root. This not only makes the searching of model elements become difficult, but it also slow down the application because Visual Paradigm tries to load all root level model elements on start up.
To solve the problem, it is recommended to keep the root clean by organizing project data with models or packages, while model is more preferred. When you right click on the project root in Model Structure tree in Project Browser, you can see the menu Model, which lets you create a model.
To move model elements from root to model, simply perform a drag and drop. To move a diagram and its children to model, right click on a model and select Diagram > Add Existing Diagram… from the popup menu and pickup the diagram to add under the model.
Although there is no agreement which defines the use of model, nevertheless modelers generally use models to differentiate stages or nature within project, such as an “as-is” model for storing diagrams and model elements about the current system, and a “to-be” model for recording blueprints of the system to be implemented. The use of model not only improve performance by reducing the number of root model elements to load, but also make developers easier to understand the model, and to look up diagram or model element they needed easier.