Adding an Existing Project to a Workspace
Add an existing project to a workspace to add a product to a multiproduct development endeavor.
In the project navigator, Control-click in the empty space below the list.
Choose Add Files to “<Workspace_Name>”.
Navigate into the folder containing the .xcodeproj file to add.
Select the .xcodeproj file and click Add.
When you need to work on two or more related projects, you can add them to a workspace so that you can create interproject relationships. For example, you can have a workspace with an app project, add a framework project to the workspace, and make the app dependent on the framework. When you build the app, Xcode builds the library first, if it needs to be built.
When adding a project to a workspace, you add the project package. A project package is a directory that the Finder displays as a file with a .xcodeproj extension. It contains information about the project, such as references to the files that are part of the project, the project’s groups, build settings, and target definitions.
After you add a project to your workspace, the project appears in the project navigator.