The modeling of manufacturing processes can be cast in a form which relies heavily on stores to and draws from object-oriented inventories, which contain the functionalities imposed on them by the other objects (including other inventories) in the model. These concepts have been implemented, but with some difficulties, for the particular case of pyrochemical operations at the DOE's Rocky Flats Plant using KEE, a frame-oriented expert system shell. An alternative implementation approach using CLOS (the emerging Common Lisp Object System) has been explored and found to give significant simplifications. 8 refs., 1 fig