Comment on ‘Technical Note – Reaching more states for control of FMS’

Uzam and Zhou (Uzam, M. and Zhou, M., 2006. An improved iterative synthesis method for liveness enforcing supervisors of flexible manufacturing systems. International Journal of Production Research, 44 (10), 1987–2030) were able to obtain a near optimal controlled model for the net S3PR with 21,562 good states. Chao's deadlock recovery scheme (Chao, D.Y., 2010. Technical Note – Reaching more states for control of FMS. International Journal of Production Research, 48 (4), 1217–1220) improves by reaching more states (21,585). However, this paper identifies a problem and proposes a solution.