A multi-agent system for dynamic integrated process planning and scheduling using heuristics

LNCS v. 7327 entitled: Agent and multi-agent systems. Technologies and applications : 6th KES International Conference, KES-AMSTA 2012 ... proceedingsPaper no. ams12-018Integrated process planning and scheduling (IPPS) is an NP-hard problem, the major research on the multi-agent system (MAS) based IPPS systems has focused on the establishment of negotiation protocols to accomplish the integration of process planning and scheduling. However, not much consideration has been paid to the dynamic factors of current manufacturing systems. In this paper, an MAS architecture is proposed to solve the dynamic IPPS problem with embedded heuristic algorithms. The proposed MAS system can be combined with a variety of heuristic methods to support dynamic process planning, scheduling and re-scheduling. As a result, the proposed MAS system for dynamic IPPS using heuristics possesses high flexibility, extensibility, and accessibility for manufacturing applications. © 2012 Springer-Verlag.link_to_subscribed_fulltex

An agent-based negotiation approach to integrate process planning and scheduling

This paper presents the development of an agent-based negotiation approach to integrate process planning and scheduling (IPPS) in a job shop kind of flexible manufacturing environment. The agent-based system comprises two types of agents, part agents and machine agents, to represent parts and machines respectively. For each part, all feasible manufacturing processes and routings are recorded as alternative process plans. Similarly, alternative machines for an operation are also considered. With regard to the scheduling requirements and the alternative process plans of a part, the proposed agent-based IPPS system aims to specify the process routing and to assign the manufacturing resources effectively. To establish task allocations, the part and machine agents have to engage in bidding. Bids are evaluated in accordance with a currency function which considers an agent's multi-objectives and IPPS parameters. A negotiation protocol is developed for negotiations between the part agents and the machine agents. The protocol is modified from the contract net protocol to cater for the multiple-task and many-to-many negotiations in this paper. An agent-based framework is established to simulate the proposed IPPS approach. Experiments are conducted to evaluate the performance of the proposed system. The performance measures, including makespan and flowtime, are compared with those of a search technique based on a co-evolutionary algorithm.link_to_subscribed_fulltex

Integrated process planning and scheduling by an agent-based ant colony optimization

This paper presents an ant colony optimization (ACO) algorithm in an agent-based system to integrate process planning and shopfloor scheduling (IPPS). The search-based algorithm which aims to obtain optimal solutions by an autocatalytic process is incorporated into an established multi-agent system (MAS) platform, with advantages of flexible system architectures and responsive fault tolerance. Artificial ants are implemented as software agents. A graph-based solution method is proposed with the objective of minimizing makespan. Simulation studies have been established to evaluate the performance of the ant approach. The experimental results indicate that the ACO algorithm can effectively solve the IPPS problems and the agent-based implementation can provide a distributive computation of the algorithm. © 2010 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

A hybrid control architecture and coordination mechanism in virtual manufacturing enterprise

The concept of Virtual Enterprise (VE), a special organization of manufacturing units and enterprises, has attracted considerable attention in recent years. Unlike traditional enterprise, VE is most suitable in production environments that experience frequent changes in product mix. To complete a complex task composed of some sub-tasks, traditional control architecture is not versatile enough to coordinate and schedule multi-site and multi-type resources, especially in resolving resource conflicts during operations. Using hybrid control architecture, VE can execute the effective control on multi-site enterprises to support the rapid response to customer demands. Coordination mechanism running through the total life cycle of VE is applied to coordinating and scheduling the requests from different tasks and resources, which make VE flexible, adaptive and robust. In this paper, the hybrid control architecture based on multi-agent technology that supports the cooperation of enterprises is presented. Coordination mechanism and the corresponding optimal models are discussed. Finally a case study is used as an illustration to present the detailed coordination mechanism.link_to_subscribed_fulltex

A hybrid control architecture and coordination mechanism in virtual manufacturing enterprise

The concept of Virtual Enterprise (VE), a special organization of manufacturing units and enterprises, has attracted considerable attention in recent years. Unlike traditional enterprise, VE is most suitable in production environments that experience frequent changes in product mix. To complete a complex task composed of some sub-tasks, traditional control architecture is not versatile enough to coordinate and schedule multi-site and multi-type resources, especially in resolving resource conflicts during operations. Using hybrid control architecture, VE can execute the effective control on multi-site enterprises to support the rapid response to customer demands. Coordination mechanism running through the total life cycle of VE is applied to coordinating and scheduling the requests from different tasks and resources, which make VE flexible, adaptive and robust. In this paper, the hybrid control architecture based on multi-agent technology that supports the cooperation of enterprises is presented. Coordination mechanism and the corresponding optimal models are discussed. Finally a case study is used as an illustration to present the detailed coordination mechanism.link_to_subscribed_fulltex

Integrated process planning and scheduling/rescheduling - An agent-based approach

This paper presents a hybrid-based multi-agent system (MAS) for integrating process planning with scheduling/rescheduling in job shops or similar kinds of flexible manufacturing environments. The approach is called Online Hybrid Agent-based Negotiation (oHAN). It employs the affected operations rescheduling approach to reschedule the operations affected directly or indirectly by the disruptions. The proposed MAS architecture comprises local agents, which are the part and machine agents, and a supervisor agent. The local agents detect the production disturbances and reschedule the affected operations via decentralized negotiations. A comprehensive set of process plan flexibilities including flexible routings and alternative machines is considered during rescheduling. The supervisor agent coordinates and monitors the rescheduling process in order to ensure the observance of a global rescheduling objective. An online hybrid contract-net negotiation protocol (oHCNP) has been established to control the interactions and communications among agents. Two types of disturbances, machine breakdown and new part arrival, are investigated in this paper. Extensive experiments have been conducted and the results show that the proposed approach is effective in solving a large-scale rescheduling problem in a reasonable time. With the introduction of the supervisory control into the decentralized negotiations, the hybrid approach is able to provide solutions with a better global performance.link_to_subscribed_fulltex

A multi-stage methodology for virtual cell formation oriented agile manufacturing

In recent years, as an emerging concept in industry, agile manufacturing has attracted considerable attention, combining virtual manufacturing cells to construct new manufacturing systems to respond to the changing market needs, especially in nonlinear processes. In this paper, a multi-stage cell formation methodology, which can help select appropriate resources and form the VCs, is presented. First, appropriate resources for completing production tasks are selected by a LP model considering the available capacity and the costs. In order to form VC in a logical mode, parts having alternative product process routings as multi-functional machines are analyzed by a resource element approach. Furthermore, some routing-based heuristic rules are introduced to optimize the candidate VCs in the form of resource elements. Finally a case study is used to illustrate the detailed formation methodology. © 2006 Springer-Verlag London Limited.link_to_subscribed_fulltex