Although you can save only an entire project, Simulation Studio enables you to open an individual project, model, or experiment.
Opening a project results in opening all models and experiments associated with that project. To open a project, model, or experiment, select File from the main menu. There are options to open a project, model, or experiment. When you open a project, a new entry is created in the Project Explorer tree for that project along with subentries for any models and experiments that reside in that particular project.
When you open an individual model or experiment, that item is included in the currently active project and a new leaf is created in the Project Explorer under the appropriate project node.