Fundamentals > Program > Pro/PROGRAM Basics > The WHICH DESIGN Menu
Initially, you can gain access to only a design listing that exists in the model. However, whenever you edit a listing, a file is created that contains the latest design specifications. At this point, two design listings exist for the same model, From Model and From File. After you successfully incorporate design changes in the model, From File is deleted, and only From Model is available.
In those cases where a From File design listing exists, the WHICH DESIGN menu displays two commands:
From Model—Retrieves a design listing built in the model.
From File—Retrieves a design for a model from an existing file named assemblyname.als or partname.pls.
From Model reflects the current state of the model, while From File includes all new instructions that you have added during the last editing session.