Holonic Manufacturing Research Articles

A holonic approach for manufacturing execution system design: An industrial application

In the age of globalisation and virtual enterprises, industrial firms are challenged by a volatile and demanding market as well as an everyday more competitive environment. As a main actor of the enterprise integration, manufacturing control systems should be designed in order to answer these necessities of reactivity and profitability in a flexible way. Holonic manufacturing system (HMS) proposes a structure organized as a loosely coupled network of communicating and cooperating agents to solve this problem. Such approach offers concrete solutions to reconfigurability and evolvability issues of manufacturing control systems. This paper presents a manufacturing execution system (MES), using the HMS concepts, and illustrates this approach on a real industrial application. 1 1 American Glass Product (AGP; www.agpglass.com) supports and partially finances this project. Such a structure is based on a typology of manufacturing system elements (products, resources, orders). Roles and behaviours for these manufacturing control elements are proposed. Product holons own reference models of products, for manufacturing execution and quality control. Resources holons are components used as bricks with local intelligent decision-making system embedded. Based on characteristics of the tasks they perform, a specialisation of resource holons is proposed. Specific heuristics are suggested for each class of resource holon. Finally, order holons are related to product demand, manufacturing task and product item. They own models of product item and a time model of the manufacturing task. Mechanisms are proposed to synchronize the execution of manufacturing tasks. These mechanisms guarantee the availability of components and enable to impose time constraints on task scheduling. This MES implements a product-centred approach, as shown by the active and opportunistic behaviour of order holons.

A generic framework to support the selection of an RFID-based control system with application to the MRO activities of an aircraft engine manufacturer

Radio frequency identification (RFID) has received a lot of attention lately. It is said that RFID tags will provide real time tracking of every item in the supply chain, providing end to end visibility and therefore total control over the supply chain. Yet, the technology is still in its infancy and it is very difficult for practitioners to distinguish between the hype created by vendors and reality. This paper, first, briefly reviews the literature on current technology, implementation studies and research trends. It then introduces a generic framework to be used in the design of an RFID based tracking and control system that should be useful for all practitioners for the selection of right type of technology. The framework is then applied to the service centre of an aircraft engine manufacturer which specialises in maintenance, repair and overhaul (MRO) activities. Two RFID part tracking systems are proposed. The first system is classical in nature and uses currently available technology. The second system exploits new concepts that are currently in development such as decentralised processing, wireless communication and holonic control that really make use of the full potential of RFID technology. It is our opinion that such intelligent systems will be the way of the future. We conclude by identifying a number of research issues that need to be solved in order to implement a true holonic manufacturing system with RFID technology.

Holarchy formation and optimization in holonic manufacturing systems with contract net

Holonic manufacturing systems (HMS) is based on the notion of holon, an autonomous, cooperative and intelligent entity to provide a econfigurable, flexible and decentralized manufacturing environment to respond to changing needs and opportunities. A set of holons that cooperate to achieve a goal forms a holarchy. How to design a mechanism to form a holarchy to achieve a goal while minimizing the overall cost is a challenge. The objectives of this paper are to propose models and develop collaborative algorithms to guide the holons to form a holarchy to coherently move toward the desired goal state ultimately. We adopt contract net protocol (CNP) to model mutual selection of holons in forming a holarchy. We formulate a holarchy optimization problem to minimize the cost subject to the feasibility constraints. To analyze the feasibility of a holarchy, a Petri net (PN) model is proposed. As classical PN models do not take into account the cost involved in firing transitions, we augment the PN model with cost functions in the problem formulation. Due to the distributed architecture of HMS, the internal structure of each potential holarchy that acts as bidder in CNP is not available to the manager. A key issue is to determine the feasibility of a holarchy without constructing the whole PN model of the given hierarchy. We study the feasible conditions for a holarchy and propose a collaborative algorithm to analyze the feasibility and award contracts to holons without constructing the whole model of a holarchy.

A distributed architecture for reconfigurable control of continuous process operations

This paper considers a new distributed approach to reconfigurable control of continuous process operations such as in chemical plants. The research is set on a premise that emerging business pressures of product customization and industrial globalization will lead to increased need for reconfigurability in process plants. The ability of processes to support dynamic and smooth reorganization of process schemes in tandem with the changing requirements of supply chains will become important in future. Conventional control approaches based on hierarchical architectures are limited in dealing with such emerging requirements due to their inflexible structures and operating rules. Instead, more distributed approaches are required which can support increased level of reconfigurability in control systems, especially at the lower levels in hierarchy where the visibility to disturbances remains high. In this paper, one such distributed approach is considered based on the concepts of holonic manufacturing and supply chain management. The proposed approach distributes the functionality of process control into several reconfigurable process elements. These elements, while having a stand-alone capability for making their own control decisions, are also able to reconfigure themselves into alternative process schemes which evolve with the changing requirements of production. An analogy between process plants and so-called dynamic supply networks or virtual enterprises is used in this paper to define the composition of reconfigurable process elements and their operations. The proposed approach is shown to offer improved process control system reconfigurability and a control architecture which is compatible with the supply chain management needs at the next higher level. The purpose of this paper is qualitative and motivational. It is aimed to propose a new research direction in the field of reconfigurable process control.

A study on integration of process planning and scheduling system for holonic manufacturing with modification of process plans

The purpose of the present research is to develop an integrated process planning and scheduling system applicable to Holonic Manufacturing System (HMS), which is one of the autonomous distributed manufacturing systems which can cope with dynamic changes in volume and variety of products. A systematic method is firstly proposed to generate a suitable schedule using the methods of Genetic Algorithm (GA) and Dispatching Rule (DR) for the multi products. A Dynamic Programming (DP) method is then proposed to modify the process plans, taking into consideration of the load balance of the machining equipments, which are obtained from the scheduling results.

A Petri net model of distributed control in a holonic Manufacturing Execution System

In a holonic manufacturing execution system, operations assignment and scheduling can be decided in real time by automatic negotiation between order holons and resource holons. Negotiation is used to conciliate the goals pursued by the software agents who constitute the control part of the holons. This paper proposes mathematical criteria to represent the agents’ goals, a game theoretic approach to analyze the possible outcomes of the negotiation process, and a Petri net model to represent the interaction protocols between order and resource agents. This model is analyzed in view of verifying the required properties of the protocol. In particular, certain conditions are proposed under which the following requirements are verified: no-blocking, selection of exactly one resource for each order, protocol termination in a bounded time.

A Study on Real-Time Scheduling of Holonic Manufacturing Systems (5th Report, Estimation Method of Future Status Without Decision Criteria of Other Holons)

This paper deals with a real-time scheduling system of the holonic manufacturing systems (HMS). In the previous papers, real-time scheduling processes have been proposed based on the utility values of the candidate holons. A simulation based procedure has also been implemented to estimate the future status of HMS and to determine the utility values based on the estimated future status. However, it was assumed that the simulation models for estimation include the model representing the decision criteria of all the holons. A new simulation based real-time scheduling method is proposed, in the present paper, to improve the estimation process, which enable all the holons to estimate the future status of the HMS without decision criteria of other holons. An estimation process is developed for the individual job holons and resource holons to estimate the future status of HMS through the simulation. Some case studies of the real-time scheduling are carried out to verify the effectiveness of the proposed method. It is shown, through case studies, that the proposed methods are effective to improve the objective function values of the individual holons.

Reconfiguration Mechanism for Holonic Manufacturing Systems

Although holonic manufacturing systems (HMS) have been recognized as a paradigm to cope with changes in manufacturing environment based on a flexible architecture, several characteristics of HMS such as re-configurability have not been characterized quantitatively. To realize these advantages, more concrete mechanisms or methodologies need to be developed. The objectives of this paper are to probe into the characteristics of reconfigurability for HMS and propose design methodologies to realize these characteristics. We formulate and study a holarchy reconfiguration problem to deal with dynamic removal/addition of holons in HMS due to failure/recovery of resources. Finding a solution from the scratch to deal with resource failures is not an appropriate approach as it may lead to chaos at the shop floor. To achieve effective reconfiguration in HMS, a viable solution must be based on the nominal configuration and cooperation of holons. We define an impact function to characterize the impact of changes due to different holons in a holarchy. A reconfiguration mechanism based on the impact function is proposed to effectively reconfigure the systems to achieve minimal cost solutions.

Towards robust and efficient planning execution

This paper presents a holonic manufacturing execution system (MES) that cooperates with a planning system. This cooperation allows to combine the robustness and flexibility of the holonic MES with the optimisation performed by the planning system. The paper investigates the effect on the global performance of this cooperation for a specific manufacturing case in a series of experiments. It compares the effect of this cooperation when the planning is optimal with regard to the manufacturing case with situations where the planning system is not optimal. More precisely, it compares the performance of the HEMS in situations where the planning systems systematically misestimates the execution time of a workstation (e.g. a poorly maintained workstation or a partially operational workstation) to situations where this is not the case. The experiments are conducted under varying work loads. Also, the effort the Holonic MES puts in finding new solutions resembling the planning is varied. Finally, the paper reports the results of the experiments and draws conclusions.

Manufacturing plant control challenges and issues

Enterprise control system integration between business systems, manufacturing execution systems and shop-floor process-control systems remains a key issue for facilitating the deployment of plant-wide information control systems for practical e-business-to-manufacturing industry-led issues. Achievement of the integration-in-manufacturing paradigm based on centralized/distributed hardware/software automation architectures is evolving using the intelligence-in-manufacturing paradigm addressed by IMS industry-led R&D initiatives. The remaining goal is to define and experiment with the next generation of manufacturing systems, which should be able to cope with the high degree of complexity required to implement agility, flexibility and reactivity in customized manufacturing. This introductory paper summarizes some key problems, trends and accomplishments in manufacturing plant control before emphasizing for practical purposes some rationales and forecasts in deploying automation over networks, holonic manufacturing execution systems and their related agent-based technology, and applying formal methods to ensure dependable control of these manufacturing systems.

Simulation Based Real-time Scheduling Method for Holonic Manufacturing Systems

Simulation Based Real-time Scheduling Method for Holonic Manufacturing Systems

1102 ホロニック生産システムにおける効用値に基づくリアルタイムスケジューリング : すべてのホロンが将来の状態の予測を行う手法(OS1-1 生産スケジューリング)

1102 ホロニック生産システムにおける効用値に基づくリアルタイムスケジューリング : すべてのホロンが将来の状態の予測を行う手法(OS1-1 生産スケジューリング)

PRODUCTION PLANNING AND CONTROL IN BIO-INSPIRED HOLONIC MANUFACTURING EXECUTION SYSTEMS

In manufacturing systems, production planning and control performs a key function. This paper discusses the production planning and control (PPC) aspects of a Bio-Inspired Holonic Manufacturing Execution Systems. The PPC system in such a bio-inspired system has a design that distinguishes it from more conventional systems. This design renders the PPC system robust and responsive when facing changes and disturbances that occur on a shop floor.

Applications of agent-based systems in intelligent manufacturing: An updated review

Agent technology has been recognized as a promising paradigm for next generation manufacturing systems. Researchers have attempted to apply agent technology to manufacturing enterprise integration, enterprise collaboration (including supply chain management and virtual enterprises), manufacturing process planning and scheduling, shop floor control, and to holonic manufacturing as an implementation methodology. This paper provides an update review on the recent achievements in these areas, and discusses some key issues in implementing agent-based manufacturing systems such as agent encapsulation, agent organization, agent coordination and negotiation, system dynamics, learning, optimization, security and privacy, tools and standards.

From system requirements to holonic manufacturing system analysis

Research on Holonic Manufacturing Systems is undergoing a huge amount of interest and developments. In spite of the great amount of effort devoted to architectures and algorithms for holonic control of manufacturing systems, there is little work about design methodologies. The present work presents a multi-agent approach for analysis of Holonic Manufacturing Systems, it is based on an abstract agent definition and the PROSA reference architecture for holonic systems. The analysis process to identify and specify holons is organized around five views of the system and integrates the advantages of proven multi-agent methodologies to the manufacturing field. An industrial case example from the ceramic domain is presented to show the characteristics of the approach.

Real-time scheduling for holonic manufacturing systems based on estimation of future status

This paper deals with a real-time scheduling system of holonic manufacturing systems (HMSs), which were proposed by an international cooperative research consortium called The HMS Consortium for Autonomous Distributed Management and Control of the Manufacturing Systems. The scheduling system generates real-time suitable production schedules, based on decision making by individual constituents named holons and their coordination. The objective of the present research is to improve the decision-making processes of the individual holons through the use of estimation process of the future status of the HMS. Procedures are developed and implemented to the individual holons, in order to estimate the future status of the HMS by applying the simulation model of the HMS. A neural network model is proposed to represent and to simulate the decision-making process of the individual holons.

A hybrid algorithm based on particle swarm optimization and simulated annealing to holon task allocation for holonic manufacturing system

Manufacturing is currently undergoing a revolutionary transition with focus shifting from mass production to mass customization. This trend motivates a new generation of advanced manufacturing systems that can dynamically respond to customer orders and changing production environments. It is becoming increasingly important to develop control architectures that are reconfigurable and fault tolerant. A holonic manufacturing system (HMS) is a system of holons that can cooperate to achieve a common goal or objective. The holonic organization enables the construction of very complex systems that are efficient in the use of resources. This paper focuses on the dynamic re-configuration and task optimization of holonic manufacturing systems (HMS). The concept of dynamic virtual clustering is extended to the control process of a holarchy or holonic organization. A task-oriented clustering mechanism and a corresponding optimization algorithm are presented as an efficient approach to the holonic control in the HMS domain. The mediator-based dynamic virtual clustering mechanism is presented firstly. Then a negotiation strategy based on the contract net protocol is proposed for cooperative action among holons. Finally, a hybrid algorithm based on particle swarm optimization (PSO) and simulated annealing (SA) for holon task allocation is described to support the optimum organization of a holarchy. The hybrid algorithm combines the high speed of PSO with the powerful ability to avoid being trapped in local minimum of SA. Simulation results show that the proposed model and algorithm are effective.

Engineering framework for agent-based manufacturing control

MAS (multi-agent systems) and HMS (holonic manufacturing systems) are enabling the vision of the Plug & Play Factory and paving the way for future autonomous production systems. This paper reviews the state of the art in implementations of agent-based manufacturing systems, and identifies the lack of engineering tools as a technological gap for widespread industrial adoption of the paradigm. The lack of tools limits the implementation of agent-based manufacturing systems within reach of only a handful of domain experts. One of the current challenges for the design and implementation of intelligent agents is the simulation and visualization of the agent societies. This issue is significant as soon as the software agent is embedded into a mechatronic device or machine resulting in a physical intelligent agent with 3D-mechanical restrictions. These mechanical restrictions must be considered in the negotiations between agents in order to coordinate the execution of physical operations. This paper presents an engineering framework that contributes towards overcoming the identified technology gap. The framework consists of a comprehensive set of software tools that facilitate the creation, simulation and visualization of agent societies. The 3D framework is innovative in fully emulating the deployed agents, recreating multi-agent negotiations and societies that coordinate and execute control of assembly operations. The documented research describes the methodology for the 3D representation of individual physical agents, the related identified objects present in the interaction protocols, and the assembly features and clustering algorithms.

Development and Applications of Holonic Manufacturing Systems: A Survey

This paper surveys the literature in the holonic manufacturing systems area in an attempt to bring together the key issues in the development and applications of holonic systems. A brief introduction presents the characteristics of today’s manufacturing environment and the requirements for next generation manufacturing systems. Then, starting with considerations about the origins of the holonic concept and its first applications in manufacturing, the paper presents the advances made in applying the holonic concept to manufacturing systems area. Several considerations for the development of holonic manufacturing systems and specific holonic system requirements are discussed. As holonic concept is considered a solution for next generation manufacturing systems, there is a significant number of applications and implementations of the holonic concept in manufacturing systems domain. The most important and relevant approaches developed so far are presented. Finally, a short conclusion and future research directions in the area are provided

An agent-based intelligent control platform for industrial holonic manufacturing systems

New revolutionary manufacturing paradigms, which take advantage of the newest emerging mechatronics, information, and communication technologies, and integrate them in a highly dynamic and agile economic, technical, and organizational manufacturing environment, are being researched and developed since the last decade of the 20th century. This new generation of manufacturing systems is referenced as intelligent manufacturing systems (IMS), and both the "holonic manufacturing system" (HMS) and the "agent-oriented manufacturing system" paradigms have been presented in recent years as the basis for making such systems a reality. This paper reports on the design and realization of an agent-based intelligent control system for industrial manufacturing systems, which covers both conventional mechatronics equipment and embedded control agents. The agent-based control software components are implemented as Windows NT services and logic control programs and interfaced via distributed component object model (DCOM) and Ethernet. Results of the application in an industrial manufacturing environment are used to show the effectiveness of the proposed "Holonic" approach.