Date of Award

Winter 1993

Document Type


Degree Name

Doctor of Philosophy (PhD)


Engineering Management & Systems Engineering


Engineering Management and Systems Engineering

Committee Director

Laurence D. Richards

Committee Director

Derya A. Jacobs

Committee Member

Billie M. Reed

Committee Member

Larry W. Wilson


Once a control structure for an integrated manufacturing system is decided upon, manufacturing activities are limited by that structure. A flexible control structure is presented as an approach for accommodating a variety of manufacturing activities, without being limited to a single control structure. A flexible control structure is one that allows multiple types of control structure in the manufacturing process. For example, both hierarchical and non-hierarchical structures may be used in a flexible structure. The properties of a flexible control structure are discussed from the point of view of graph theory.

Control structures for automated manufacturing are difficult to evaluate without actually setting up a pilot production system. Since this is often not possible for reasons of expense or equipment availability, it would be advantageous to be able to simulate alternative control structures for their various characteristics. In this research, flexible control is demonstrated with a factory simulation of an automated on-line/post-process inspection system. Factory simulations present special problems when used for evaluation purposes. An approach to using a factory simulation is developed, and alternative control structures are evaluated with respect to their fault tolerance characteristics. The results of this research indicate that flexible control may be cost effective when a large variety of manufacturing activities must be accommodated, but further research is needed to confirm precisely how wide a range and what types of activities would justify this approach.