An automated manufacturing system (AMS) is a computer-controlled system which can work twenty-four hours a day. It can automatically finish various kinds of jobs by using shared resources such as robots, machines, and automated guided vehicles. In an AMS, raw parts are processed concurrently in a pre-established sequence to compete for limited system resources. The competition may cause deadlocks (Coman et al., 1971; Gligor and Shattuck, 1980) when some processes keep waiting indefinitely for the other processes to release resources. Deadlocks are a highly undesirable situation that must be considered in AMSs since a system in a deadlock situation always means that the whole system or a part of it is blocked. Deadlocks often oset the advantages of these systems. For example, deadlocks in a flexible manufacturing system (FMS) can cause unnecessary cost, such as long downtime and low use of some critical and expensive resources, and may lead to catastrophic results. Therefore, many researchers do more and more work to deal with deadlock problems in AMSs.