I want to introduce the concept of Holonic Manufacturing, as I believe Computer Integrated Manufacturing (CIM) will continue to move in this direction now that connectivity, interoperability and cloud-based networking are present. Areas of security, rules based systems and distributed architecture will be addressed in later blogs as we develop this Holonic theme.
HOLONIC MANUFACTURING
Manufacturing has changed a lot since its beginning, especially for the last decades. These changes are not only technology-related, but also concern the way customers interact with the manufacturing system, the environment that must be preserved, the shorter product's life-cycle, etc.
Until a few years ago, the Computer Integrated Manufacturing concept was considered satisfactory enough for treating enterprise/manufacturing requirements. However, taking into account a new set of organizational and economic concepts, it becomes clear that the centralized CIM approach is not the answer. On the contrary, the requirements for today's and future manufacturing systems suggest autonomy, distribution, and flexibility, while stressing the need for co-ordination amongst production units. It is expected that rigid, static and hierarchical manufacturing systems will give way to systems that are more adaptable to rapid change.
It is at this point that agent technology is adequate. An agent is an autonomous entity, maybe intelligent, that pursuits its own goals and, eventually, it may cater for the user's ones. Some authors would like to augment this definition in order to incorporate social ability, mental behavior (e.g. knowledge, beliefs, desires, and intentions), and learning.
A Multi-Agent System (MAS) is a population of agents that exhibit social behavior and are capable of interacting with each other in a co-operative fashion, while simultaneously each agent may pursue individual objectives. This interaction assumes some kind of communication language (e.g. KQML and perception of the surrounding environment. The use of a multi-agent architecture will make the decisions be taken in a decentralized way.
Agent-based systems are "best suited for applications that are modular, decentralized, changeable, ill-structured and complex", and with a "great number of interactions among components".
On the other hand, a manufacturing system may be characterized by:
On the manufacturing arena, these two paradigms (DAI and MAS) are best represented by the concept of Holonic Manufacturing Systems (HMSs). The idea behind HMSs is to provide a dynamic and decentralised manufacturing process, in which humans are effectively integrated, so that changes can be made dynamically and continuously.
As Agent-based Manufacturing relies on the notion of agent, HMSs are based on the notion of Holon. Arthur Koestler coined the term "Holon" from a combination of Greek holos (whole) with the suffix on which, as in proton or neutron, suggests a particle or part. A Holon means simultaneously a whole (to their subordinated parts) and a dependent part when seen from the inverse direction. Thus, a Holon can be made up of other holons.
This aggregation of holons inside other holons is called holarchy. An HMS is a holarchy that integrates the entire range of manufacturing activities from order booking through design, production, and marketing to achieve the agile manufacturing enterprise.
This article (and image) are quoted from a good resource paper on the Holonic Manufacturing subject (see http://sic.ici.ro/sic2000_2/art02.htm.) My source acknowledgement goes to:
Paulo Sousa & Carlos Ramos
Departamento de Engenharia Informática
Instituto Superior de Engenharia do Porto (ISEP/IPP)
Rua São Tomé, s/n, 4200 Porto, Portugal
HOLONIC MANUFACTURING
Manufacturing has changed a lot since its beginning, especially for the last decades. These changes are not only technology-related, but also concern the way customers interact with the manufacturing system, the environment that must be preserved, the shorter product's life-cycle, etc.
Until a few years ago, the Computer Integrated Manufacturing concept was considered satisfactory enough for treating enterprise/manufacturing requirements. However, taking into account a new set of organizational and economic concepts, it becomes clear that the centralized CIM approach is not the answer. On the contrary, the requirements for today's and future manufacturing systems suggest autonomy, distribution, and flexibility, while stressing the need for co-ordination amongst production units. It is expected that rigid, static and hierarchical manufacturing systems will give way to systems that are more adaptable to rapid change.
It is at this point that agent technology is adequate. An agent is an autonomous entity, maybe intelligent, that pursuits its own goals and, eventually, it may cater for the user's ones. Some authors would like to augment this definition in order to incorporate social ability, mental behavior (e.g. knowledge, beliefs, desires, and intentions), and learning.
A Multi-Agent System (MAS) is a population of agents that exhibit social behavior and are capable of interacting with each other in a co-operative fashion, while simultaneously each agent may pursue individual objectives. This interaction assumes some kind of communication language (e.g. KQML and perception of the surrounding environment. The use of a multi-agent architecture will make the decisions be taken in a decentralized way.
Agent-based systems are "best suited for applications that are modular, decentralized, changeable, ill-structured and complex", and with a "great number of interactions among components".
On the other hand, a manufacturing system may be characterized by:
- Its functions (e.g. production planning, production scheduling, inventory, etc.), which can be seen as modules;
- As it was already referred, the traditional CIM centralized architecture is not satisfactory for today's manufacturing requirements; new manufacturing systems must be decentralized manufacturing systems;
- Physically, a manufacturing system is based on resources (e.g. numeric control machines, robots, AGVs, conveyors). The number and configuration of these resources may change during the system's life time;
- Since the manufacturing process is a dynamic one (e.g. suppliers and consumers in a supply chain may change many times) it is impossible to know the exact structure or topology of the system, thus being ill-structured;
- The number of products and orders, as well as different alternative production routes, count for the highly complex nature of the manufacturing systems.
On the manufacturing arena, these two paradigms (DAI and MAS) are best represented by the concept of Holonic Manufacturing Systems (HMSs). The idea behind HMSs is to provide a dynamic and decentralised manufacturing process, in which humans are effectively integrated, so that changes can be made dynamically and continuously.
As Agent-based Manufacturing relies on the notion of agent, HMSs are based on the notion of Holon. Arthur Koestler coined the term "Holon" from a combination of Greek holos (whole) with the suffix on which, as in proton or neutron, suggests a particle or part. A Holon means simultaneously a whole (to their subordinated parts) and a dependent part when seen from the inverse direction. Thus, a Holon can be made up of other holons.
This aggregation of holons inside other holons is called holarchy. An HMS is a holarchy that integrates the entire range of manufacturing activities from order booking through design, production, and marketing to achieve the agile manufacturing enterprise.
This article (and image) are quoted from a good resource paper on the Holonic Manufacturing subject (see http://sic.ici.ro/sic2000_2/art02.htm.) My source acknowledgement goes to:
Paulo Sousa & Carlos Ramos
Departamento de Engenharia Informática
Instituto Superior de Engenharia do Porto (ISEP/IPP)
Rua São Tomé, s/n, 4200 Porto, Portugal
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