Cell control by intelligent objects-a new dimension of production control systems

The flexible automation of manufacturing processes requires sophisticated information technology. Today´s production control systems do not meet the requirement of market driven manufacturing processes. A solution to correct these deficiencies of production control systems is the object oriented approach. It allows one to compose systems from portable and reusable components. For this reason, the production control system, described in this paper, is composed of intelligent manufacturing objects and a global manager. Each of these intelligent manufacturing objects represents a real existing device of the plant which has to be scheduled, controlled, and monitored. The global manager, also object oriented programmed, performs the central and coordinating tasks of the production control system and handles the communication between the system and the user, and moreover with the PPS-system. Compared with conventional production control systems this new development has important advantages. First, the flexibility of the system referring to changes in the manufacturing system is enhanced significantly. Furthermore, the system can easily be distributed on parallel computers for speed-up and can also be scaled accordingly to the requirements of the plant. The speed-up enables new dimensions in rescheduling and dynamic process control because the functions of scheduling, controlling, and monitoring are distributed