Factory Information Systems

Design and Implementation for Cim Management and Control

John Gaylord

• Publisher: CRC Press
• Year: 2020
• Print ISBN: 9780824773892
• eBook ISBN: 9781000146646
• Edition: 1
• Topic: Business
• Subtopic: Operations
• Index: Business

This book tells how to develop a successful factory information system to manage and control computer integrated manufacturing (CIM)operations. It is directed and dedicated to those people who are involved in the preservation and enhancement of historical manufacturing strength.

1
Introduction to Computer Based Manufacturing Systems

1.1 INTRODUCTION

A factory is itself a society. It is composed of diverse people with a larger common goal but with differing and sometimes conflicting subgoals and incentives. The relationships between these people and the resources they control is very complex, as in any society. The speed and accuracy with which they communicate, resolve conflicts, and make decisions directly affects the productivity and efficiency of their manufacturing operation. This first chapter describes computer based systems that are used to assist in this social process of communication and decision making.

To function societies have evolved languages, communication systems, transportation techniques, and rules of behavior. Like production operations they have defined objectives and devised ways of measuring progress toward achieving these objectives. As societies grew they made contact with other adjacent societies which had different languages, ways of communicating, transportation, and rules of behavior. In much the same way, the factory is in contact with its related organizations such as research centers, product engineering functions, marketing operations, and financial control groups, many of which are often remote from the manufacturing site.

Like isolated societies, manufacturing plants have also evolved their own unique languages, ways of communication, and rules of behavior which differ from product design or marketing societies. Thus when manufacturing engineers and product design engineers endeavor to move a new product into manufacturing these differences can result in misinterpretations and loss of information transfer. Another example is the difference in incentives and rules of behavior for production control and marketing groups. These differences lead to conflict between optimizing the manufacturing operation and satisfying the customer demand. Conflicts must, therefore, be resolved at relatively high levels both within the manufacturing organization and between it and the other related macrosocieties necessary to run the larger business.

For the larger business to succeed all the management and control systems of the various macrosocieties should be connected together. Within the factory the FIS system should be connected to all levels of management including the production machines. The concept of total optimization expressed by this interconnection is called Computer Integrated Manufacturing or CIM.

The objective of this first chapter is to describe in general terms the various systems which comprise the composite CIM system. It becomes readily apparent that as these systems interact with each other, the same problems experienced by expanding societies reoccur-languages are incoherent, communication systems are incompatible, and behavior is governed by different rules. This, in summary, is today’s CIM challenge.

1.2 COMPUTER INTEGRATED MANUFACTURING (CIM) SUBSYSTEMS

Various computer based manufacturing systems shown in Figure 1.1 are used to improve the quality, speed, and cost effectiveness with which new products are created and produced. When connected together with the effective communications, described in Chapter 7, these systems form a computer integrated manufacturing (CIM) network. The realization of this network is the current goal of many manufacturing companies because it is essential for their survival in an increasingly competitive world.

Figure 1.1 Computer based systems used for product evolution.

The scope is broad and the jargon is confusing when one is first exposed to these systems. To simplify this situation they have been reduced to the five generic types listed in Table 1.1. The functions performed by these systems are first described in summary. This is followed by a more detailed explanation of how they work together to provide decision support and control for the factory.

Table 1.1 Generic Computer Based Manufacturing Systems

1. Systems Integration

Factory Information System (FIS)

2. Design Support

Computer Aided Design (CAD)

Computer Aided Engineering (CAE)

Computer Aided Design and Drafting (CADD)

Factory Planning

3. Manufacturing Control

Computer Aided Manufacturing (CAM)

Computer Assisted Process Planning (CAPP)

Process Monitoring and Control (PMC)

Flexible Manufacturing Systems (FMS)

Automated Material Handling and Storage (AMHS)

Distributed Monitoring and Control (DMC)

Scheduling

4. Testing

Computer Aided Testing (CAT)

Automatic Test Equipment (ATE)

5. Material Acquisition

Material Requirements Planning (MRP)

The first of these generic systems integrates many of the others into the CIM network. This factory information system (FIS) ties together design, manufacturing, test, and factory management systems, monitors overall manufacturing performance, and assists with local production floor inventory control and scheduling. It is the “backbone” of computer integrated manufacturing (CIM).

Design support systems such as computer aided design (CAD), computer aided engineering (CAE), computer aided design and drafting (CADD), and factory planning primarily support engineering, design, and drafting activities. They also significantly improve product manufacturability and directly provide many of the software “programs” used by CAM systems to guide and control production machines. The factory planning system is used by industrial engineers to plan new production facilities and to modernize old ones. The planning is accomplished by using a very sophisticated workstation which contains many tools for simulation, graphics, and financial analysis.

The control of manufacturing is accomplished using computer aided manufacturing (CAM), process monitoring and control (PMC), flexible manufacturing systems (FMS), computer assisted process planning (CAPP), automated material handling and storage (AMHS), product tracking and flow control (PT and FC), distributed monitoring and control (DMC), and scheduling systems. In addition to controlling manufacturing processes these systems simultaneously supply much of the data used by the factory information system (FIS) to monitor production performance. The CAPP system is used to define efficient groups of manufacturing processes by simulation using machine capacity data, human work capability factors, and optimum line balance techniques. A FMS system uses programmable robots, transfer devices, and processing machines to provide rapid change-over for assembling or forming many different products in small, intermixed batches. FMS makes possible a manufacturing strategy often referred to as “lot-size one.” The AMHS system transports materials to and from workstations, maintains accurate inventories, and executes warehouse and distribution functions. The product tracking system monitors the location and state of product as it traverses the various steps of the manufacturing process. Flow control systems monitor the status of machines and dynamically alter the movement of product to different machines or process steps as conditions and schedules dictate. A scheduling system advises marketing, production control, supervisors, and forepersons regarding future product movement based on market requirements and the analysis of available resources.

Computer aided testing (CAT) and automatic test equipment (ATE) accomplish product adjustment and assure product quality. CAT systems, like CAM systems, also supply information to an FIS. Material acquisition is accomplished by using a material requirements planning (MRP) system tied closely to a scheduling system. It uses the FIS to monitor the status of order completion and material stocks. It generates a master schedule plan for material acquisition by using subsystems such as bill-of-material, inventory-transaction, scheduled receipts, shop-floor-control, capacity-requirements-planning, and purchasing.

The systems that comprise CIM are still in their infancy. As more powerful and cost effective computers evolve, these systems will be economically feasible to implement in small and mediumsized manufacturing plants as well as the larger installations where they now are used. Today the major impediment to CIM implementation is the difficulty of connecting these systems to each other. They have yet to be effectively integrated. One major reason has been the lack of a generic technical standard for communication. This standard, called the Manufacturing Automation Protocol or MAP, is rapidly being established by cooperating industrial and international organizations. By the late 1980s implementation of these standards using local area networks will occur permitting the “factory of the future” to be finally realized if data structures are adequately defined.

Integration has also been inhibited because some of the system functions cross traditional boundaries of classical organization responsibility. There is therefore a lack of middle management incentive to integrate. A third curtailment for integration is the un-abashed exposure computer based manufacturing systems give to problems and performance deficiencies. This has, for example, significantly retarded the use of computer systems for monitoring and control of manufacturing in some communist countries where management requires greater flexibility in performance reporting. These systems are enthusiastically used only by confident groups of people who are comfortable with facts, flexibility, and change in pursuit of improved performance. If properly designed, integrated, and used, they have great potential for improving resource utilization as discussed in the next chapter. Taken together they assist in the evolution of new products through design, development, production, and distribution.

Each of the systems listed in Table 1....

Table of contents

• Cover
• Title Page
• Copyright Page
• Preface
• Contents
• 1. Introduction to Computer Based Manufacturing Systems
• 2. What to Monitor and Control: The Needs Analysis
• 3. Structured Systems Analysis
• 4. Product Tracking and Flow Control
• 5. Statistical Control Charting
• 6. Decision Support and Automation Using Artificial Intelligence
• 7. Communication Networks for Factories
• 8. Factory Information System Implementation
• Index