The use of a factory simulation to evaluate a flexible control structure for integrated manufacturing

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. The definition and the properties of a flexible control structure are discussed from the point of view of graph theory. The flexible control structure and the alternative control structures are demonstrated with a factory simulation of an automated on-line/post-process inspection system. All the control schemes are evaluated with respect to their fault tolerance characteristics, operability, and expandability. 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