Information technology for the processses of manufacturing.

Kamble Prashant, G. ; Uppin, M.S. ; Hebbal, S.S. 等

Abstract: The current paper describes the significance and application of information technology to different processes of manufacturing organization. Further, the key issues the must be considered in the analysis of flow of the information in a manufacturing organization have been highlighted and certain research activities have been described which involve the application of information technology for the manufacturing activities

Key Words: Enterprise modeling, Agent based manufacturing, Object oriented approach

1. INTRODUCTION

Today's world market environment is rushing towards its total globalization, and is characterized by ever increasing pace in production and decreasing product cycle times. The common trends that are observed in today's manufacturing systems are: numerous competitors, market globalization, a steadily increasing complexity of business processes, a highly turbulent production environment, development and application of new product technologies, increase in product variety and decrease in product volumes, increase in delivery reliability and products are expected to be of low-cost, high quality and high reliability. Therefore businesses that are more responsive to market changes and more sensitive to customers needs are more likely to survive and thrive in such environment. Global competition and rapidly changing customer requirements are forcing major changes in the production styles and configuration of manufacturing organizations. Hence, manufacturing systems and strategies will need to satisfy the following requirements [Shen and Norrie].

--An individual or collective manufacturing enterprise will have to be integrated with its related management systems and its partners via networks.

--Manufacturing systems will have to accommodate heterogeneous software and hardware in both their manufacturing and information environments.

--It must be possible to dynamically integrate new subsystems (software, hardware, or manufacturing devices) into or remove existing subsystems from the system without stopping and reinitializing the working environment.

--Manufacturing facilities must be able to rapidly reconfigure and interact with heterogeneous systems and partners.

Over the past two decades a large number of manufacturing systems, production models and philosophies have been developed by exploring the advanced manufacturing techniques that satisfy the above requirements in order to deal with the global competition and changing needs of the customer. Typical examples are CAD/CAM/CAE/CAPP/CIM, FMS, Design for manufacturing, Agile manufacturing, Intelligent manufacturing systems, Agent based manufacturing system.

The common characteristics of all these manufacturing systems / models are: a) application of computers to all most all the activities right from design, planning, manufacturing, quality control to customer services b) automation of most of the activities c)integration of different activities, d)application of large amount of data stored in different databases e)depends upon the information technology for the successful implementation of these manufacturing systems and production strategies. The current paper describes the significance of following components of information technology for the development and application of above mentioned advanced manufacturing systems and production models; Distributed Database systems, Object Oriented Programming approaches, Agent based technology and Artificial Intelligent Techniques. Further certain research activities have been described which involve the application of information technology for the manufacturing activities.

2. INFORMATION MANAGEMENT

The above discussion shows that efficient and effective information flow is essential for any manufacturing organization in order to improve its competitiveness in global market. The available literature reveals the following are the key issues the must be considered in the analysis of flow of the information in a manufacturing organization.[Prashant et al]

a) Every unit of organization should achieve enterprise integration, which means each unit of the organization will have access to information relevant to its task and will understand how its actions will impact other units of the organization.

b) Abundant, accurate information can enable very efficient operating decisions and better forecasts but the cost of building and installing systems to deliver this information can be very high.

c) Integration is challenging for the manufacturing enterprise because the manufacturing activities, including design, planning, simulating and tracking differ in format.

d) Although computerized applications in manufacturing are widespread, information processing is still fragmented since these computer applications have been developed without taking a general frame work into account and the hardware and software used are produced by a range of different firms.

e) Typically, a manufacturing organization involves a distributed intelligent manufacturing environment. The following IT based approaches / concepts can be applied to manufacturing organizations which enable them to satisfy the requirements listed above.

2.1 Distributed database systems

A distributed database is a set of databases stored on multiple computers that typically appears to applications as a single database. Consequently, an application can simultaneously access and modify the data in several databases in a network It means adistributed database is integrated database which is built on top of a computer network rather than on a single computer. The data which constitute the database are stored at the different sites of the computer network, and the application programs which are run by the computers access data at different sites. Databases may involve different database management systems, running on different architectures, that distributes the execution of transactions. A Distributed Database Management System (DDBMS) is defined as the software that handles the management of the Distributed Database and makes the operation of such a system appear to the user as if it were a centralized database. Some of the components of a distributed database management system are : Distributed transaction manager, a program that translates requests from the user and converts them into actionable requests for the database managers, which are typically distributed A Database Manager,a software which is responsible for processing a segment of the distributed database. User Request Interface which is typically a client program that acts as an interface to the Distributed Transaction Manager and accepts user's requests for transactions

2.2 Agent based manufacturingAn agent is autonomous, goal-oriented software that operates asynchronously, communicating and coordinating with other agents as needed [Grabner et al]. For the manufacturing applications it is a software entity that has a set of protocols which govern the operations of the manufacturing entity, a knowledge base, an inference mechanism and an explicit model of the problem to solve [w]. Agents communicate and negotiate with the other agents, perform the operations based on the local available information and may pursue their local goals. However, the overall performance of the agent-based system has to be satisfactory even from a global point of view and depends primarily on the protocol that regulates the negotiations among the agents and on the quality of the data used to make these decisions. Technically, agents possess sufficient knowledge and inferential capability to behave in a manner that would be classified as "intelligent" if performed by a person. Organizationally, agents are entrusted with sufficient authority to make commitments for users. This enables them to represent their principals and adhere to the same corporate rules, policies and procedures required to be followed by people in the organization.

2.3 object oriented approach

The object-oriented paradigm has been started from software programming and design i.e. in the field of software programming the introduction and definition of abstract data types, objects and classes of objects has originated a new approach and a new modularization principle known as object oriented. Following this principle the software architecture of an enterprise can be decomposed in terms of objects organized in hierarchies. Object oriented modeling merges both functional and data aspects. An object is an entity that incorporates its own data and functions that manipulate [Keogh and Gianini] it. It possesses an identity, a state (data structures which record the current situation of an object) and a set of functions that are also called as methods. In other wards an object contains two types of functional components: attributes and methods. Attributes form the basic description of an object's states and also form the connections with other objects. Methods are discrete pieces of procedural code identified by a name that describe the potential behaviour of the object.

3. PROPOSED WORK

The pressure from increased market competition is making Computer Integrated Manufacturing (CIM) a necessity First step in any improvement effort in order to realize CIM is to achieve a complete, common, and correct understanding of the enterprise. Enterprise models are used to achieve this understanding. An Enterprise Model is an interactive representation of the organization, its processes, and resources. For the manufacturing enterprise, this model defines a unique set of business processes that are performed to design, plan, produce and market the enterprise's products. It identifies following: what the enterprise does, who does it, how it is done, what resources are needed and available. However the most important aspect is, how these elements relate to each other. Hence, enterprise modeling can be used to construct models of organizations for purposes of predicting and estimating the impact of change within an organization brought about by changes in the external environment. Unlike the other systems a real enterprise has a very complicated data architecture. Most of the data will be held in large number of package systems, for which the details of data structure may be unknown and most data is duplicated across a number of systems, with significant variations in quality, format, and meaning. Agent technology provides a natural way to address the above issues in order to design and implement distributed intelligent manufacturing environments and provides a software architecture for managing the integrated enterprise for realizing CIM. It views the enterprise as composed of a set of intelligent agents, each responsible for one or more activities in the organization and each interacting with other agents in planning and executing their responsibilities. An agent is an autonomous, goal-oriented software that operates asynchronously, communicating and coordinating with other agents as needed. The agents do not transfer and process data on the other computer, but rather perform tasks and transfer results to the user They represent the programs that can be initiated on a single host and then made to migrate from host to host over a network. At each host, a process can be spawned which will provide a "black-box" view into that host's information. This provides access to necessary information, while maintaining privacy for company sensitive information. Thus it can support the requirement for supply chain. The multi agent system which include mobile agents which are in the form of programs that can be initiated on a single host and then migrate from host to host over a network. Rules can be established to determine the migration path wherein the mobile agent determines its own next host. At each host a process can be designed, similar to some decision support system. Therefore, the application of agent based approach for developing the proposed enterprise model is identified as the area for the long term research activity which has the major objective of providing significant contribution to modern manufacturing enterprises to face global competitiveness. Further, it may be noted that, the technique of object oriented analysis and design because of their direct liaison with the physical reality, the modularization and reusability they offer, appear highly promising for providing a frame work for the representation and integration of manufacturing information. In a manufacturing organization, objects represent the resources, roles and responsibilities in the organization. Since object oriented approach permits to design the data structures such that they characterize the objects, which can communicate with each other through functions they enable to present the integrated picture of an enterprise. Hence, it is planed to develop an object-oriented architecture, which describes the enterprise in terms of objects, classes, attributes, services and interrelations etc. and with the properties an object-oriented approach can be used as a natural framework for the management of manufacturing information and integrating heterogeneous components of manufacturing enterprise.

4. REFERENCES

Grabner, M, Gruber F, Klug L, Stockner W--Agent Technology: State of the Art The Economic Chamber of Upper Austria

Jim Keogh and Mario Gianini--Object Oerientd Programming: Principles and practices,Dreamtech Publishers NewDelhi., 2004

K.Prashant G, A. Samrani S. S. Hebbal -Agent Based Approach for Supply Chain Management Belgaum,.May--2004 P.No.23.

Weiming Shen and Douglas H. Norrie-"Agent-Based Systems for Intelligent Manufacturing: A State-of-the-Art Survey " URL: http://imsg.enme.ucalgary.ca/