Click for next page ( 15


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 14
2 SUMMARY OF SITE VISITS Members of the Committee visited five manufacturing companies now using computer-aided des ign and computer-aided manufacturing sys t ems . These companies have all been leaders in using computerized automation and were in the process of integrating existing capabilities or implementing new integrated systems. The site visits were designed to gain a better understanding of data requirements, data flow, and linkage problems associated with these systems. The companies visited were McDonnell Aircraft Company, Deere & Company, Westinghouse Defense and Electronics Center, General Motors Corporation, and Ingersoll Milling Machine Company. They were chosen to represent leaders in computer-integrated manufacturing (CIM) in a variety of industries, both defense and commercial, large and smaller companies, with product lot sizes ranging from one to many. There are, of course, other companies that have been leaders in the use of CIM, but the experience of these five companies covers a variety of products, company sizes, and corporate styles. The Committee also met with the managers of the three major government programs that relate to computer-integrated manufacturing: the NASA/Navy Integrated Program for Aerospace Vehicle Design (IPAD); the Air Force's Integrated Computer-Aided Manufacturing (ICAM) program; and the National Bureau of Standards ' Automated Manufacturing Research Facility (AMRF). This chapter summarizes the information that the Committee collected as a result of its talks with industrial and federal managers. The results of the interviews are reflected in a broader context in Chapter 3. DEFINITION OF COMPUTER-INTEGRATED MANUFACTURING The companies visited agreed with the Committee's definition of computer-integrated manufacturing. As stated in Chapter l, a manufacturing enterprise can be said to be integrated when: all the processing functions and related managerial functions are expressed in the form of data, 14

OCR for page 14
15 these data are in a form that may be generated, transformed, used, moved and stored by computer technology, and these data move freely between functions in the system throughout the life of the product, with the objective that the enterprise as a whole have the information needed to operate at maximum effectiveness. The companies stressed the participation of people in integration. They view CIM as a combination of computer-based data, automation, and people working harmoniously at, a high level of effectiveness at all times. People are an important part of the system, which should be recognized in any definition of CIM. The companies also spoke about CIM as involving continual f low of information among the several functions, such as that shown in Figure 1 of Chapter 1. Such a flow is required whether the integra- tion of functions is occurring manually among people, automated via computer systems, or by a combination of the two . INCENTIVES FOR COMPUTER-INTEGRATED MANUFACTURING Each company visited viewed its business from both global and domes tic perspectives and considered integration technology a primary need for supporting its business strategy. They all cited competition from foreign nations and a need to improve responsiveness to meet worldwide demand as a major strategic issue and incentive for CIM. One company noted that it was continually forced to improve on its own technology, which was being exported through offshore sales and through offset agreements that require production of parts and assemblies by foreign manufacturers. Demand for quality and responsiveness in the U.S. marketplace was another incentive. Each of these leading companies introduced computer integration only after serious consideration of the resources required, the risks, and the expected benefits. The efforts in these companies focused on improving the information flow within the factory and particularly between the engineering design and production functions. The companies capitalized on the capabilities of computers to improve communication and control of the enterprise. The managers interviewed remain unsatisfied with the adequacy and timeliness of the information flow and believe that improvement in data communication will further improve corporate productivity and product quality. PLANNING FOR INTEGRATION Long-Range Planning Each of the five companies has a formal plan for achieving CIM. Each plan has a broad, long-term perspective; in at least one of the

OCR for page 14
16 companies, the plan looks 10 years into the future. The companies set yearly objectives and budgets and measure progress toward those objectives. - These pioneers had to learn what has become obvious today: that it is enormously difficult to link heterogeneous groups of hardware and software. They now demand that new systems they acquire be able to link with existing equipment. The companies emphasized the need to create communication, understanding, and acceptance among people in various functions before expecting to succeed in automating the information flow among these functions. Their integration plans required a clear understanding of the information flow among the several functions. Justification of CAD/CAM Integration The companies visited generally had started their CAD/CAM activities in at least two separate areas. Automation of the engineering design process often began with computer-aided drafting and progressed to computer-aided design and analysis, while automation in production typically began with numerically controlled machines and evolved to computer-aided production facilities. These early efforts were often described as "islands of automation." As additional computer-aided technology was added, the need became clear to bridge the islands. These companies independently concluded that the usual financial measures, such as return on investment, were inadequate for assessing the results of integration. These traditional measures have been useful for highly focused investments. In the integration of computer-aided technologies, however, both costs and benefits span multiple functions and are difficult to capture by traditional accounting procedures. The best measures, these companies say, are responsiveness, productivity, quality, lead time, design excellence, flexibility, and work-in-process inventories. Progress is also measured in terms of its consistency with corporate objectives. Each company found that the introduction of coordinated CAD/CAM systems brought substantial improvements in productivity. A few examples: o Printed circuit board assembly from design release to delivered product was reduced from 18 weeks to 4 weeks. Inventory was reduced from three months' supply to one month. By passing geometric data instead of drawings from design to numerical control programming, the man-hours per part programmed was reduced by well over one-third. A computer-integrated flexible manufacturing system reduced total personnel in routing, purchasing, torch programming, inspection, and machine operation by one half for the same output.

OCR for page 14
17 The companies studied have realized substantial gains cumulatively during the integration process. The values shown below are representative of the intermediate benefits of 10- to 20-year efforts. Further benefits are expected to accrue as full integration is approached. Benefits Achieved Reduction in engineering design cost Reduction in overall lead time Increased product quality as measured by yield of acceptable product Increased capability of engineers as measured by extent and depth of analysis in same or less time than previously Increased productivity of production operations (complete assemblies) Increased productivity (operating time) of capital equipment Reduction of work in process Reduction of personnel costs 15-30% 30-60% 2-5 times previous level 3-35 t imes 40-70% 2-3 times 30-60% 5-20% One large conglomerate! made a special study of the results achieved by a diverse group of independent companies through the modernization of production management systems. Production management systems are narrower than CIM, but the data indicate that significant savings have already resulted from the application of this portion of CIM technology. The findings of that study are in Appendix B. Management Commitment to CIM The direct involvement of top management was found to be the key to successful CIM programs in the companies visited. At one company, for example, systems designers were spending 60 percent of their time reconciling data bases, and action by the chief executive officer (CEO) was necessary to bring about change. He initiated a review of the data structure and data access needs and ordered a halt to new computerization during the two years necessary to create a new, unified data base. At another company, insufficient visibility of top management support caused the CIM effort to founder. With the creation of an executive vice presidency for technology, the company regained focus and direct involvement of top management in CIM.

OCR for page 14
18 Without exception, the senior managers selected highly competent people to plan and conduct their CIM activity and gave them clear authority, individual accountability, and a clear understanding of how their work linked to company goals. People on the CIM teams had informal, clear, frequent, and in-depth communication with the top management of their companies. During the 20 to 30 years that these companies have been building the infrastructure for computer integration, they have learned a number of important lessons. Significant progress required the total commitment of strong technical staff and management teams. Managements had to learn, in the words of one, "to be smart, not sophisticated." The implication was that the existence of new technology did not necessarily mean that it was appropriate or necessary for the company to use it. Progress toward CIM accelerated with understanding of the CIM plan at all levels of the organization and acceptance of the plan as a corporate goal. Good human relations and shared goals were a precursor for acceptance. - WHAT LEVEL OF CAD/CAM INTEGRATION WILL BE ACHIEVED? The Committee attempted to discern whether the companies visited would achieve the level of integration described in our definition. The issue turned out to be not if they would, but when. Estimates ranged from five to ten years, based on today's perception of integration. Nonetheless, substantial technical, social, and financial barriers remain, as detailed in Chapter 3. The companies visited expressed concern that they were in a small minority. With few companies making such efforts on a large scale, progress will be limited: the greater the number of companies working on CIM, the greater the benefits to all from shared experience. Furthermore, the large companies visited viewed the lack of CIM capabilities in their suppliers as an impediment to their own CIM plans . The few suppliers that had computer links to the company that did final product assembly were able to respond quickly to design changes. All of the companies visited were faced initially with a relatively narrowly trained work force. They expressed a general need to provide improved training in new skills for nearly everyone, including the machine operator, the engineering work force, and the management team. These companies today have broad skill bases because of their extensive computerization effort over a long period. Other companies that undertake CAD/CAM integration will find the lack of skilled people one of their most serious problems. The availability of skills and training could very well determine how rapidly they can take advantage of this new technology.

OCR for page 14
future. 2. Determine the factors that will be keys to the success of this business in the future. 3. Develop a long-range plan that defines product evolution, rate of new product introduction, mission and objectives of facilities, and existing and planned capabilities. 4. If the previous steps have disclosed opportunities for improvement through development of CAD/CAM systems, the chief executive officer is then in a position to start the project. 19 STARTING A CAD/CAM INTEGRATION EFFORT The more experienced companies have evolved their own methods of selecting, developing, and implementing CAD/CAM activities. The pioneering companies often underestimated the time and money required to learn how best to undertake these activities. Companies starting computer integration today can learn from the experience of the pioneers. The Air Force ICAM program has outlined key steps2 for successful implementation of a CAD/CAM system at minimum cost. Information gathered on the site visits supports the outline: 1 . De termine how the company is going to run its business in the In all of the companies visited, the CEO set up a multi- functional task force, led by a top level official. The functional representatives had departmental decision-making authority. This team determined the direction of the project, supported by internal and consulting expertise as required. Industry is using several systems development cycles or steps today. One being used extensively was developed by the Air Force ICAM program and is called the Program Life Cycle. It guides the documentation of sys tem development and has eight key steps: (1) Needs analysis (2) Requirements definition (3) Preliminary design (4) Detail design (5) Construction & verif ication testing (6) Integration & validation testing (7) Implementation & user acceptance (8) Maintenance & support Companies take diverse approaches to CIM. Most of those visited started with narrow applications and gradually linked them to broaden the integration effort. The one company that planned to start by putting in place a comprehensive system found it necessary to abandon the effort and to work instead toward more modest, intermediate milestones. Each company had different strengths on which to build. Most began with a pilot integration project in one division, typically the one with the greatest willingness to take the risk of making the

OCR for page 14
20 technological and organizational changes required for CIM. Managerial organization often is an impediment to computer integration, particularly if lines of communication do not exist among the appropriate parties. FEDERALLY FUNDED CAD/ CAM PROGRAMS The three major federal programs directed at the integration of computerized systems in engineering design and production are directed at the solutions of problems that much of industry faces. No single program, however, has addressed the integrated system as a whole. Rather, IPAD addresses engineering design, ICAM addresses the architecture of manufacturing and the control of production, and the AMRF assists medium-sized and other companies to use shop-floor automation. Federal technology programs tend to be reasonably applicable to many companies and therefore exactly applicable to none. Thus, companies seeking to integrate can find many useful technological accomplishments in these programs, but each company must customize its own integrated system. To the extent that these companies have access to information on technological accomplishments elsewhere, creation of a CIM system will be easier. Integrated Program for Aerospace Vehicle Design The initial objective of the Integrated Program for Aerospace Vehicle Design (IPAD) was to develop a computer software system for use by the U.S. aerospace industry in the design of future vehicles. This system was intended to reduce time and cost substantially and to foster improved vehicle performance. The work began in 1976 at the Boeing Commercial Airplane Company with the preparation of specifications and preliminary design for an IPAD system. It was to support the full engineering activities of a large aerospace organization composed of many people working on many projects at several levels of design over long periods of time. The project was broken into four phases: 1. Requirements for the IPAD program were defined by an examination of the aerospace design process and its interactions with manufacturing. - 2. Integrated information processing requirements for aerospace design were established. 3. A software specification and preliminary design of a full IPAD system were prepared to support the requirements for aerospace design. 4. A partial version of the full IPAD system was developed, resulting in prototype software that demonstrated the feasibility and technology needs of data base management systems which could support the intent of a fully integrated system.

OCR for page 14
21 The requirements were for a general purpose: an interactive computer-aided engineering system capable of supporting engineering data associated with the design process and its interfaces with production. The system would serve management and engineering staffs at all levels, including the production processes. The preliminary sys tem des ign focused on a dis tributed, heterogeneous machine environment in which data base management technology and networks played critical roles in the total solution. In 1978, NASA decided to concentrate IPAD resources on two areas: data management and networking between heterogeneous machines. Large improvements can be made in the way'information is managed and shared, which IPAD demonstrated in its data base management system (DBMS) prototype, called IPIP. It is a multimodal, multiuser, multilevel schema, concurrent access DBMS that includes the data definition language (DDL) and data manipulation language (DML) required to solve engineering problems. IPIP supports multiple data models (relation, hierarchy, and network). These features promote a high degree of data independence. The {PAD network system provides ultrahigh-speed exchange of data between heterogeneous equipment. It provides the equivalent of levels 3 through 6 of the International Standards Organization (ISO) seven- level model of communications. The system was the first to use Network System Corporation's Hyperchannel to provide process-to- process communications (levels 1 and 2 of the ISO model) between different computers (a VAX 11/780 and a CDC CYBER 835) using different operating systems. In summary: 1. The IPAD studies of engineering processes provided a broad understanding of the system requirements that will have to be supported to reach integration. 2. The IPAD research work provided useful prototype software for advanced network communication and engineering data management, illustrating the nature of future products. 3. IPAD tutorials, reports, and applications established the advanced technology requirements of engineering data management, data schema, and integration of engineering applications with an engineering data management system. 4. The development of a software prototype helped stimulate vendors to produce new products in the areas of data management and network communications. Recent NASA reviews of the projects led to the conclusion that IPAD had fulfilled to a large extent its original research objective. Consequently, NASA and Boeing are formulating a redirection of the project.

OCR for page 14
22 Integrated Computer Aided Manufacturing While NASA and the Navy have sponsored IPAD, an engineering design system, the Air Force has sponsored the Integrated Computer Aided Manufacturing (ICAM) program, a production system. Both types of system are required for computer-integrated manufacturing. Air Force studies in 1975 disclosed increased complexity of weapons systems, declining quality and productivity, and increased procurement lead times in much of the industry supporting Air Force procurement. In response to these studies, the Air Force created the ICAM program in 1976 to achieve major increases in productivity in aerospace batch manufacturing through widespread application of computer based, fully integrated factory management and operation systems. ICAM had a nine-year budget of almost $100 million. The demonstration of an integrated sheet metal center at Boeing Military Airplane Company in 1985 will culminate the program. The Air Force approach was to create integrated management systems that tie all of the key production functions--product development, production, and product support--into a common data base. Production, the principal concern of ICAM, includes planning of facilities, assembly, fabrication, quality control, production control, inventory control, and data collection. Early efforts were directed at identifying the key barriers to more effective integration. Through the use of industry/university consortia, ICAM then identified and demonstrated ways to break down these barriers in the industrial environment. Additional effort is directed at transferring the technology. Product Definition Data Interface Perhaps the most formidable technological barrier to CAD/CAM integration is the transfer of geometry and instructions across the design-production interface. The government program addressing this barrier most directly is the Product Definition Data Interface (PDDI) project within the ICAM program. It seeks to provide a framework for exchange of digital data defining the geometry of the product, which ing drawing. (IGES), managed by the National Bureau of Standards, established the initial base for direct digital exchange of graphics data. It has been adopted as a standard by the American National Standards Institute (ANSI Y14.26M, Section 2-4) and is being used by major vendors and users. - ICES provides a product definition data interface for limited applications. Full integration will require a complete product description that is accessible and understandable by users at all points in the manufacturing process. Advanced manufacturing technologies in numerical control, robotics, automated process planning, and inspection, and their integration into a cohesive system, are practically impossible if the product cannot be defined by digital data that can directly feed these processes. serve the function of the conventional engineer The Initial Graphics Exchange Specification

OCR for page 14
23 The PDDI project is likely to extend the applicability of ICES considerably. Its objective is twofold, as shown in Figure 2. First, it will identify the current state of ICES implementation through the appl ication o f test procedures for current graphics sys tems . Second, it will define long-range manufacturing needs and demonstrate a prototype interface for product definition data that meets these needs. To these ends, the project will: analyze needs for product definition data in manufacturing, using sample aerospace parts define an automated framework for a Product Definition Data Interface develop a data format and utilities required to support the PDDI prove the concept of the PDDI through demonstration of the utility software The PDDI prototype system is intended to serve as the information interface between engineering and all manufacturing functions that use today's blueprint, including process planning, numerical control (NC) programming, quality assurance, and tool design. It will be demonstrated with an advanced NC programming system and an advanced process planning system. The system also will be operated with two commercial CAD systems to demonstrate its general applicability. Automated Manufacturing Research Facility The Automated Manufacturing Research Facility (AMRF) of the National Bureau of Standards serves as an engineering "tes t bed" to supply U.S. industry with "new ways of making precise measurements of machined parts derived from NBS standards that will be developed using capabilities inherent in modern, computer-controlled machinery."4 A second objective is to encourage the modernization of U.S. industries through the development and common use of standard interfaces between various types of equipment. Standard interfaces would enable heterogeneous components of a manufacturing system to communicate without a need for custom-designed interfaces. The challenge is to develop standard procedures, protocols, and interfaces that will support current and emerging technology without stifling innovation. The AMRF seeks the most practical incremental route to automation for small to medium sized companies. It uses domestically built, commercially available machines, most of which involve two or more components made by different manufacturers. The modular, hierarchical software is believed by NBS to be the most flexible program available today. The program was first demonstrated in November 1983, and enhancements are planned over the next two or more years. AMRF research is aimed at inspection of parts while they are being processed. With advanced machine-control systems and new computer technology, the computer can be programmed to compensate continually for known errors in machine movement, using sensors to determine

OCR for page 14
24 Figure 2 o ._ ._ _ ._ 3 0 ~ e _ ' co y E an ..... II '.~e le.',, ~ . a) 5 O E c`, C) 1 E o 11 an UJ a) _ Q. ~ 5 O ~ it a, in an In Cal ._ Q LIZ Cl) . a) cn $ E u, an In c' ._ Q ._ cn CD a) ~0 J _ ~ l l l E CL ~7 LOU t _ _ ~ _ im a, Q E ~o 1' y cn ~: cn cn ._ ., _ t o 1i {1' CO . E 0 ~ C~ ~n _ c~ ~ _ ~c :~ E ~ _ E 0 ~ _ C~ C: _ _ _ _ cn cn 0 0 o ._

OCR for page 14
25 machine condition. An important question still to be answered is how to calibrate precisely a measurement process that is deeply embedded in the manufacturing process and that depends on the machine-tool control system. Most large industrial firms now have heterogeneous computer-controlled equipment and the skills and resources to work out the complex interface problems of integration. However, 87 percent of discrete parts manufacturing companies have fewer than 50 employees.5 Smaller companies, with limited resources, cannot invest in large- scale automated systems all at once. Yet large companies that purchase parts from smaller companies find that their own CIM efforts are slowed by their suppliers' lack of CIM abilities. Because the AMRF system is a research facility to be used by government, industry, and academia to evaluate different systems concepts, it has an emulation capability. Emulation is the ability to perform the computer functions of one computer or hardware element in another computer so that, from a logical basis, the rest of the system does not recognize the substitution. Any piece of equipment, group of machines, or subsystem can be caused to emulate another subsystem, so that the AMRF hardware and software can be used to evaluate a system using alternative choices of hardware and software. NOTES 1. Richard H. Fabiano, General Electric Co., Bridgeport, CT. Each of these steps is defined in detail in the Air Force document IDS150120000C, ICAM Documentation Standards, 15 September 1983. 3. Ibid. Michael Baum, "Automated Manufacturing Research Facility (AMRF) Fact Sheet" (November 1983~. 5. John A. Simpson et al, "The Automated Manufacturing Research Facility of the National Bureau of Standards," Journal of Manufacturing_Systems (vol. 1, no. 1) p. 19.