Synthesis of fault-tolerant supervisor for automated manufacturing systems: a case study on photolithographic process

A discrete event dynamic system (DEDS) approach is utilized to improve the reliability of a system from the fault-tolerance viewpoint. We propose a systematic way to classify faults and failures quantitatively and to find tolerable fault event sequences embedded in DEDSs. After this, the synthesis of a fault-tolerant supervisory control system is investigated. A case study of a photolithographic process in a semiconductor manufacturing system is provided to illustrate these techniques.