COMPUTER-INTEGRATED
MANUFACTURING

Computer-integrated manufacturing (CIM) is the use of computer techniques to integrate manufacturing activities. These activities encompass all functions necessary to translate customer needs into a final product. CIM starts with the development of a product concept that may exist in the marketing organization; includes product design and specification, usually the responsibility of an engineering organization; and extends through production into delivery and after-sales activities that reside in a field service or sales organization. Integration of these activities requires that accurate information be available when needed and in the format required by the person or group requesting the data. Data may come directly from the originating source or through an intermediate database according to Jorgensen and Krause. CIM systems have emerged as a result of the developments in manufacturing and computer technology. According to Kusiak the computer plays an important role integrating the following functional areas of a CIM system:

• Part and product design. There are four phases that are crucial in part and product design. They include preliminary design, refinement, analysis, and implementation.
• Tool and fixture design. Tooling engineers using computer-aided design (CAD) tools to develop the systems or fixtures that produce the parts.
• Process planning. The process planner designs a plan that outlines the routes, operations, machines, and tools required. He or she also attempts to minimize cost, manufacturing time, and machine idle time while maximizing productivity and quality.
• Programming of numerically controlled machines and material handling systems.
• Production planning. There are two concepts used here including materials requirement planning (MRP) and machine loading and scheduling.
• Machining. This is part of the actual manufacturing process, including turning, drilling, and face milling for metal removal operations.
• Assembly. After they are manufactured, parts and subassemblies are put together with other parts to create a finished product or subassembly.
• Maintenance. Computers can monitor, intervene, and even correct machine malfunctions as well as quality issues within manufacturing.
• Quality control. This involves three steps including system design, parameter design, and tolerance design.
• Inspection. This stage determines if there have been errors and quality issues during the manufacturing of the product.
• Storage and retrieval. These tasks involve raw materials, work-in-process inventory, finished goods, and equipment.

CIM ORIGIN

The term computer-integrated manufacturing was coined by Dr. Joseph Harrington in his 1974 book bearing that name. Until the 1970s, the most aggressive and successful automation was seen in production operations. Discrete parts manufacturing used highly mechanized machines that were driven and controlled by cams and complex devices such as automatic screw machines. Process manufacturers made use of these cam-driven controllers and limit switches for operations such as heat treating, filling and canning, bottling, and weaving states Robert Thacker of the Society of Manufacturing Engineers. The historical approach to automation focused on individual activities that result in the incorporation of large amounts of computerized activities. In the 1980s, managing information became an important issue.

CIM BENEFITS

According to the U.S. National Research Council, CIM improves production productivity by 40 to 70 percent, as well as enhances engineering productivity and quality. CIM can also decrease design costs by 15 to 30 percent, reduce overall lead time by 20 to 60 percent, and cut work-in-process inventory by 30 to 60 percent. Managers who use CIM believe that there is a direct relationship between the efficiency of information management and the efficiency and the overall effectiveness of the manufacturing enterprise. Thacker's view is that many CIM programs focus attention on the efficiency of information management and the problems that come with it instead of developing new and more sophisticated manufacturing machines, material transformation processes, manufacturing management processes, and production facilities. Computer-integrated manufacturing can be applied to nonmanufacturing organizations by changing the manufacturing focus toward a service orientation. CIM and Job Definition Format (JDF) are becoming increasingly beneficial to printing companies to streamline their production process.

THE CIM PLAN

A plan for a CIM system should provide a description of projects for automating activities, assisting activities with technology, and integrating the information flows among these activities. The planning process includes six crucial steps:

• project activation
• business assessment
• business modeling
• needs analysis
• conceptual design
• CIM plan consolidation and economic analysis

This process, according to Jorgensen and Krause, also acts as a building block for the future of the organization integrating these functions in order to diminish them as an impediment to integration.

CONCEPTUAL DESIGN

The conceptual design of a CIM environment consists of individual systems that fulfill the required capabilities, an overall architecture incorporating the systems and the communication links, and a migration path from the current systems architecture. Functional requirements must be compared to the current inventory of systems and available technology to determine system availability. Jorgensen and Krause state that the following techniques are used in satisfying system requirements:

• exploiting unused and available functional capabilities of current systems;
• identifying functional capabilities available for, but not installed on, current in-house systems;
• locating systems that are commercially available but not currently in-house;
• recognizing state-of-the-art technology that is not immediately commercially available on a system;
• foreseeing functional capabilities of systems on the technical horizon; and
• determining whether the requirement is beyond the capabilities of systems on the technical horizon.

MANAGING A CIM

Managers must understand that short-term goals must support the long-term goal of implementing a CIM. Top management establishes long-term goals for the company and envisions the general direction of the company. The middle management then creates objectives to achieve this goal. Upper management sees the focus as being very broad, whereas middle management must have a more narrow focus.

In deciding to implement a CIM, there are three perspectives that must be considered: the conceptual plan, the logical plan, and the physical plan. The conceptual plan is used to demonstrate a knowledgeable understanding of the elements of CIM and how they are related and managed. Thacker goes on to say that the conceptual plan states that by integrating the elements of a business, a manager will produce results better and faster than those same elements working independently.

The logical plan organizes the functional elements and logically demonstrates the relationships and dependencies between the elements. Thacker details that it further shows how to plan and control the business, how to develop and connect an application, communications, and database network.

The physical plan contains the actual requirements for setting the CIM system in place. These requirements can include equipment such as hardware, software, and work cells. The plan is a layout of where the computers, work stations, robots, applications, and databases are located in order to optimize their use within the CIM and within the company. According to Thacker, sooner or later it becomes the CIM implementation plan for the enterprise.

CIM is challenged by technical and cultural boundaries. The technical challenge is first complicated by the varying applications involved. Thacker claims that it is also complicated by the number of vendors that the CIM serves as well as incompatibility problems among systems and lack of standards for data storage, formatting, and communications. Companies must also have people who are well-trained in the various aspects of CIM. They must be able to understand the applications, technology, and communications and integration requirements of the technology.

CIM cultural problems begin within the division of functional units within the company such as engineering design, manufacturing engineering, process planning, marketing, finance, operations, information systems, materials control, field service, distribution, quality, and production planning. CIM requires these functional units to act as whole and not separate entities. The planning process represents a significant commitment by the company implementing it. Although the costs of implementing the environment are substantial, the benefits once the system is in place greatly outweigh the costs. The implementation process should ensure that there is a common goal and a common understanding of the company's objectives and that the priority functions are being accomplished by all areas of the company according to Jorgensen and Krause.