This invention provides a system and method for guiding the workpieces to optimal positions to train an assembly system that is generally free of the use of a CMM or similar metrology device. The system and method expresses the image features of the workpieces, when they are in their respective stations, in a common coordinate system. This ability allows a user to visualize the result of assembling the workpieces without actually assembling them, in a “virtual assembly”. The virtual assembly assists guiding placement of workpieces in respective stations into a desired relative alignment. The system and method illustratively generates a composite image using the images from cameras used in guiding the workpieces that helps the user visualize how the part would appear following assembly. The user can reposition the images of workpieces in their respective stations until the composite image has a desired appearance.