A natural step in the evolution of a model is to create a new version, starting by saving with a new name from the Editor. When you do this, the Editor will also make a corresponding copy of the original results workspace file (if there is one, and if there is not already a workspace file with the new name) in order to carry forward the working environment with the new model.
Note: As the Editor and Results programs are separate processes, the Editor can only copy the most recently saved workspace file from disk; so you may wish to save the workspace for the original model before saving the new version from the Editor.