A new information exchange method named recursive propagation is proposed in order to solve job shop scheduling problems in decentralized manufacturing systems. Each machine only has to notify the change of its plan to other machines which are directly influenced by the change. The effect of the change in the plan is directly fed back to the machine which notified the change. The change in the plan is notified to all the machines concerned by simple one-to-one communication among the machines, and the influence of the change caused by its action can be reported to the initiator through the same communication path. The proposed method is applied to a 20×10 job shop scheduling problem, and the feasibility of this approach is verified by simulations.

Decentralized Job Shop Scheduling by Recursive Propagation Method

New architectures of manufacturing systems have been proposed aiming at realizing more flexible control structures of manufacturing systems which can cope with dynamic changes in volume and variety of products. They are so called as holonic manufacturing systems, autonomous distributed manufacturing systems, random manufacturing systems and biological manufacturing systems. The objective of the present research is to develop an integrated process planning and scheduling system which is applicable to the holonic manufacturing systems. In the previous paper, procedures were proposed to recognize the machining features from the product model. A systematic method is proposed, in this paper, to select suitable machining sequences and sequences of machining equipment, by applying the genetic algorithm (GA) and the dynamic programming (DP) methods.

Study on Process Planning System for Holonic Manufacturing

Study on Process Planning System for Holonic Manufacturing:Process Planning considering both Machining Time and Cost

This paper deals with a real-time scheduling system of HMSs (Holonic Manufacturing Systems) . A scheduling process based on the utility values have been proposed and applied to the realtime scheduling problems of the HMSs in the previous report. It was shown that the proposed methods generate suitable schedules from the view point of the objective functions of the individual holons in the HMSs. A new real-time scheduling method is proposed, in the paper, to consider both the objective functions of the individual holons and the whole HMSs. In this method, all the pareto optimal combinations of the resource holons and the job holons are generated based on the objective function values of the individual holons. Following this, a most suitable combination is selected from the pareto optimal ones, based on the objective functions of the whole HMSs, such as total make span and total tardiness. It is shown, through case studies, that the proposed method is effective to improve the production schedules from the viewpoint of the objective functions of the whole HMSs in comparison with the previous method.

https://www.jstage.jst.go.jp/article/kikaic1979/72/720/72_720_2613/_pdf

A Study on Real-Time Scheduling of Holonic Manufacturing Systems (4th Report, Multi-objective Optimization Process for Individual Holons and Whole HMSs)

Recently, new distributed architectures of manufacturing systems are proposed, aiming at realizing more flexible control structures of the manufacturing systems. Many researches have been carried out to deal with the distributed architectures for planning and control of the manufacturing systems. However, the human operators have not yet been discussed for the autonomous components of the distributed manufacturing systems. A real-time scheduling method is proposed, in this research, to select suitable combinations of the human operators, the resources and the jobs for the manufacturing processes. The proposed scheduling method consists of following three steps. In the first step, the human operators select their favorite manufacturing processes which they will carry out in the next time period, based on their preferences. In the second step, the machine tools and the jobs select suitable combinations for the next machining processes. In the third step, the automated guided vehicles and the jobs select suitable combinations for the next transportation processes. The second and third steps are carried out by using the utility value based method and the dispatching rule-based method proposed in the previous researches. Some case studies have been carried out to verify the effectiveness of the proposed method.

A Study on Human Oriented Autonomous Distributed Manufacturing System —Real-time Scheduling Method Based on Preference of Human Operators

This paper deals with an object-oriented modeling of an autonomous distributed manufacturing system and its application to the production scheduling. The architecture of the autonomous distributed manufacturing systems is discussed from the viewpoint of information processing in the manufacturing system. An object-oriented modeling method is applied to describe the decision-making activities and the communication activities of the components, such as the manufacturing devices and the workpieces. The activities of the objects are discussed in detail from the viewpoint of the production scheduling. The contents of the objects are clarified, and the part-of relations and the is-a relations between the objects are also established. A distributed production scheduling method is proposed on the basis of the autonomous decision making of the individual components and their coordinations.

Tatsuya Ninagawa

Papers

Design and Management of Autonomous Distributed Manufacturing System. Modeling and Application to Production Scheduling.