1. A system including a computer for creating a set of end product configurations from a series of intermediate configurations, each said end product comprising a subassembly of instantiated parts, each said instantiated part belonging to a class, said class being represented by a prestored template capable of being displayed on a display, said instantiated parts comprising a set of resources, needs and attributes, each said instantiated part optionally comprising a subassembly of instantiated parts and each said instantiated part selectable by said system according to a set of user-supplied descriptions and a set of said instantiated part's needs and resources, said system comprising: a storage means for storing said user-supplied descriptions of the class of instantiated parts; a retrieval means for retrieving said prestored templates from said storage means, said templates providing said user-supplied descriptions; display means for displaying said templates on a display; a first processor means for creating instantiated parts from said templates; and a second processor means for combining a plurality of said instantiated parts together to form said intermediate configurations for storage and later retrieval.