Supervisory control and diagnosis of systems are having more importance in the manufacturing process. There exist several frameworks for synthesis of supervisors and diagnosers for discrete event systems (DES). However, no general methodology applicable for any system and with an implementation orientation is universally accepted. Nevertheless, implementation is extremely important and one of the main goals for research in the future highly automated manufacturing world. In this paper, we propose a benchmark manufacturing cell and some experiences of designing supervisors and diagnosers are carried out using the Ramage and Wonham framework.