TECHNICAL AND ECONOMIC STUDIES OF FLEXIBLE MANUFACTURING SYSTEMS

Abstract

This thesis concerns the study of the economic and technical aspects of FMS. It essentially consists of two sections to describe these two aspects. The economic section examines the present financial evaluation techniques used by local firms to justify the acquisition of flexible manufacturing systems. Although sophisticated methods have been developed and are available, firms are still using the payback period method primarily due to a lack of adequate data. A method based on the incremental rate of return is proposed. It requires the use of a minimal amount of information to assist management to decide on the purchase of flexible manufacturing systems. The technical section presents a strategy to improve the reliability of flexible manufacturing systems. Contingency management, which incorporates fault tolerance techniques, is used to restore the system from an erroneous state. Four stages of fault tolerance have been implemented: error detection, damage confinement and assesment, error recovery and fault treatment and continued service. A generic model for the robot assembly cell is formalised. Discussions will be centred on an existing work-cell which has been enhanced by the error recovery strategy. Communication schemes are implemented to enable automatic execution of the strategy.