Group technology applications in manufacturing operations through the computer system

The typical manufacturing facility is constantly developing new product designs and related manufacturing processes. The increased volume of new designs and processes causes rapid and inefficient construction of product designs and manufacturing processes. Many parts and manufacturing processes are developed over the life cycle of a production facility with no organized means of cataloging this past and present data. This procedure is extremely ineffective because there is no way to determine if a part or process has been previously developed. The constant “reinventing of the wheel” creates a tremendous waste of manpower and cost.

One approach to solving this problem is through the use of group technoogy. Group technology is the identification and grouping of similar parts and processes in order to take avantage of their similarities in the design and manufacturing process. Parts and processes can be grouped under a classification and implemented with a coding system. Concurrently, the number of parts and processes can be reduced by putting them in a “family.” This “family” has common characteristics such as shape, size, color, tolerance or production operations.

For handling and manipulation of this data, a computer system has been developed. The computer system would set up a reporting format that would classify, code and group the parts and processes, so the user can analyze if a previously designed process or part can be used in the current system and/or if a better layout can be feasible.

Many advantages such as reduced inventory cost, increased facility space and better utilization of manpower are but a few of the benefits from this system.     

Implementing mass customization

Total Customer Satisfaction today can mean embarking on “Mass Customization”: giving every customer a product tailored specifically to his or her needs. In the past, manufacturing was usually “high volume, low mix”, characterized by keeping costs down with economies of scale, or “low volume, high mix”, incurring costs and time for changeovers and special handling. Today's mass customization, however, can result in a challenging manufacturing environment with both high volume and high mix, where customers expect individualized products at the same price they paid for mass-produced items. Meeting this challenge requires changes in the manufacturing processes. Equipment must be more flexible. Most important are the computer systems which support the manufacturing enterprise. Never has data been so essential to define, control, and monitor manufacturing as with mass customization. Motorola's product lines — from the pagers with millions of possible options, to the cellular phones and semiconductors — are all experiencing the move to mass customization. This presentation will describe some Motorola examples and the methods used to achieve world-class manufacturing under these conditions.     

Intelligent manufacturing and environmental sustainability

The definition of sustainability which is generally adopted is: “meeting the needs of the present generation without compromising the ability of future generations to meet their own needs” (World Commission on the Environment and Development, 1987. Brundtland report). The EU MDG7 report, describes environmental sustainability as: “…meeting current human needs without undermining the capacity of the environment to provide for those needs over the long term…” (UN, 2005a). Over the past decade public concern about sustainable development has profoundly transformed attitudes and to a lesser extent practices in manufacturing industries. A sustainable approach to design and engineering involves evaluating where a product or system has the greatest environmental impact and then prioritising strategies which reduce that impact. There is hardly any industry sector in which the management of environmental sustainability is not of significant relevance. The degradation of pristine ecosystems, global warming, and unprecedented energy usage, has become key issues for all of earths ‘tenants’. It is essential that all facets of design and manufacturing take action on environmental sustainability concerns through appropriate strategies, and endeavour to implement standards such as the ISO 14001, and accommodating related legislation as a foundation for sustainable manufacturing. This paper discusses the sustainability challenges of the industrial world, the sustainable management issues they face, and the strategies they might employ, while maintaining corporate responsibility and gaining competitive advantage.     

A heuristic grouping procedure for component family formation in a cellular manufacturing environment

A heuristic clustering procedure is introduced for grouping purposes in a cellular manufacturing environment. The procedure uses the concepts of “edge-cut” and “cut-set” of graph theory in combination with a similarity measure to group the objects. An experiment was conducted to compare twelve different variations of the procedure when used for component family identification. Two measures of performance are used to select the most suitable variation of the procedure and a numerical example is given for the variation.     

General structure and characteristics of quick response production system

The diversification and shorter production cycles urge manufacturers to shift their production systems from “make to stock” to “make to order” or an intermediate production system between them. The present paper deals with a production system developed by some manufacturers to meet requirements in the last decade. The system, which we call “Quick response to orders production system” or in brief “quick response production system (QRPS)”, is characterized by two key factors, i.e., “acceptable response time” and “semifinished product.” An acceptable response time is decided through the explicit or implicit approval of customers beforehand and manufacturers guarantee to ship products within an acceptable response time in a stochastic sense by processing the semifinished product according to customer order. As a result, manufacturers are able to reduce the inventory of finished products, while customers are able to enjoy the diversification of products and a stable supply from manufacturers. The general structure and characteristics of QRPS are discussed primarily from a quantitative point of view and a numerical example is shown to assist in understanding the design and operation of QRPS.     

The future of artificial intelligence (AI) in manufacturing

Artificial Intelligence (AI) is now among the buzzwords in manufacturing. Articles are written about various aspects of AI in manufacturing and some of these are discussed by Miller in “Artificial Intelligence: Applications for Manufacturing” [1]. Most of those authors extol the virtues of AI in manufacturing. From some of the literature, one might draw the conclusion that AI will solve all of our problems.

AI technologies are very sophisticated and are not going to easily accomodate the “noise” of the factory floor. We can see some of these techniques beginning to make inroads into manufacturing, but the road to full-scale implementation will be a rocky one.     

Biometric perils and patches

Biometrics authentication offers many advantages over conventional authentication systems that rely on possessions or special knowledge. With conventional technology, often the mere possession of an employee ID card is proof of ID, while a password potentially can be used by large groups of colleagues for long times without change. The fact that biometrics authentication is non-repudiable (hard to refute) and, yet, convenient, is among its most important advantages. Biometrics systems, however, suffer from some inherent biometrics-specific security threats. These threats are mainly related to the use of digital signals and the need for additional input devices, though we also discuss brute-force attacks of biometrics systems. There are also problems common to any pattern recognition system. These include “wolves” and “lambs”, and a new group we call “chameleons”. An additional issue with the use of biometrics is the invasion of privacy because the user has to enroll with an image of a body part. We discuss these issues and suggest some methods for mitigating their impact.     

CIM—the integration of manufacturing and information systems

The integration of computers within the manufacturing environment has long been a method of enhancing productivity. Their use in many facets of a manufacturing enterprise has given industries the ability to deliver low-cost, high-quality competitive products. As computer technology advances, we find more and more uses for new hardware and software in the enterprise. Over a period of time, we have seen many “islands” of computer integration. Distinct, fully functional hardware and software installations are a common base for many industries. Unfortunately, these islands are just that, separate, distinct and functional but non-integrated. The lack of integration within these information systems make it difficult for end users to see the same manufacturing data. We are finding the need for a “single image” real-time information system to provide the enterprise with the data that is required to plan, justify, design, manufacture and deliver products to the customer. Unfortunately, many industries have a large installed base of hardware and software. Replacement of current systems is not a cost-justified business decision. An alternative would be the migration of current systems to a more integrated solution. The migration to a computer-integrated manufacturing (CIM)-based architecture would provide that single image real-time information system.

The effort and skills necessary for the implementation of a CIM-based architecture would require active participation from two key organizations: Manufacturing and information systems (I/S). The manufacturing engineers, process engineers and other manufacturing resource would be the cornerstone for obtaining requirements. The ability to effectively use I/S is a critical success factor in the implementation of CIM. I/S has to be viewed as an equal partner, not just as a service organization. Manufacturing management needs to understand the justification process of integrating computer systems and the “real” cost of integration versus the cost of non-integrated manufacturing systems. The active participation of both organizations during all phases of CIM implementation will result in a effective and useful integrated information system.     

Integration of neural networks and genetic algorithms for an intelligent manufacturing controller

This paper addresses the development and implementation of a “controller” for a single manufacturing machine. This prototype will serve as an important tool to study the integration of several functions and the utilization of status data to evaluate scheduling and control decision alternatives. The emphasis is on creating a prediction capability to aid in assessing the long-term system performance impact resulting from decisions made and environmental changes. This prediction capability is implemented by using neural networks, simulation, and genetic algorithms. Neural networks predict the behavior of different sequencing policies available in the system. The contribution of the genetic algorithms to the decision-making process is the development of a “new” scheduling rule based on a “building blocks” procedure initiated by the neural networks     

Transaction exchange management systems for successful systems integration

The objective of this paper is to discuss the strategy to be taken by computerized information system managers and developers in the evolving era of computer integrated manufacturing (CIM). Specifically, more concentration should be directed towards a standardized methodology for the management and handling of the transaction data which flows between two or more systems, rathr than upon the hardware and software technology used to “connect” those systems.     

Personalization of internet telephony services for presence with SIP and extended CPL

This paper discusses issues of personalization of presence services in the context of Internet Telephony. Such services take into consideration the willingness and ability of a user to communicate in a network, as well as possibly other factors such as time, address, etc. Via a three-layer service architecture for communications in the session initiation protocol (SIP) standard, presence system basic services and personalized services (personal policies) are clearly separated and discussed. To enrich presence related services, presence information is illustratively extended from the well known “online” and “offline” indicators to a much broader meaning that includes “location”, “lineStatus”, “role”, “availability”, etc. Based on this, the call processing language (CPL) is extended in order to describe presence related personalized services for both call processing systems and presence systems using information such as a person’s presence status, time, address, language, or any of their combinations. A web-based system is designed and implemented to simulate these advanced services. In the implementation, personal policies are programmed by end users via a graphic user interface (GUI) and are automatically translated into extended CPL. The simulation system clearly displays when, where and what CPL policies should be used for the provision of personalized presence services and call processing services. Policy conflicts are also addressed by setting policy priorities in the system.     

An exponential membership function for fuzzy multiple objective linear programming

The operator “min” is one of the most frequently used aggregation operators in fuzzy decision. However, this operator is the softest operator and no allowance is made for any compensation. The “product” and other operators, some of them may be compensatory, are seldom used because of the nonlinearity of the resulting problem. In this paper, an exponential, instead of linear membership function is proposed. The advantages of using exponential membership are two fold. First, the resulting problems can be transformed to linear ones when the “product” and several other nonlinear aggregate operators are used. Secondly, exponential representation is more realistic than the linear ones usually used for some practical applications.     

A strategic decision support system for supply network design and management in the semiconductor industry

This paper presents a strategic decision support system (DSS) which has been conceptualized and designed by SEMATECH^* to assist the large semiconductor manufacturing organization in managing its extensive supply chain network. This DSS has been named “Manufacturing Enterprise Model” or “MEM”. MEM ties each factory and its primary metrics to the rest of the business enterprise to assess how changes in wafer fabrication affect other factories, the distribution system, and customer deliveries. The model is intended to be used to evaluate future factory concepts and to assist business planners in strategic decisions about product allocation and major resource/facility planning.     

Groupware in Practice: Expected and Realized Benefits

This article examines the usage of groupware at 22 consulting firms and attempts to answer the questions: “What groupware functions are used by consultancies?” “What benefits were expected and to what degree were these benefits realized?” and “What factors accounted for any realization gaps?”     

Generalized boundary conditions on the basis of a deformable-cell method: Free surfaces, density interfaces and open boundaries

In the numerical analysis of flows, we need to treat various types of boundary conditions; in particular, in the fields of oceanophysics or hydraulics, “free surface”, “density interface” and “open boundary” have been considered difficult to treat. On the basis of a deformable-cell method, the cells dividing the fluid can be deformed in accordance with the moving boundaries, as in the arbitrary-Lagrangian-Eulerian method, and these boundary conditions are systematically treated with a “generalized boundary equation”. The validity of this method is shown by a flow with a free surface, a density interface and an open boundary.     

Effect of rework strategies on cycle time

In batch manufacturing, a fraction of the batch, or “lot,” may require reworking because its members fail to conform to standards. A rework station “undoes” the previous operation, so that the nonconforming members can go through the same operation additional times. This paper explores how policies dealing with these nonconforming members affect the cycle time of a facility.

Two different operating policies can be followed. In one, the “mother” lot is held back while the “child” sub-lots are reworked, after which all members are reunited for the next operation. In the other, the mother lot is allowed to proceed to the next operation while the child is held back; reworked members are then introduced by one of three methods: In the first, the reworked members of each mother lot are introduced by themselves. In the second, a minimum order quantity of reworked members is designated and a new lot introduced when this level is reached. In the third, the reworked members are added to the next mother lot that visits the operation.

In this paper, queuing models are developed for these policies, and the policies are simulated with regard to cycle time. Simulation of a wafer fabrication model is used to determine the effectiveness of these policies and their impact on cycle time.     

Daily output planning: Integrating operations research, artificial intelligence, and real-time decision support with APL2

A key decision faced each day, shift, or time period at a semiconductor manufacturing facility is how many wafers or lots should it commit to produce at each operation, over a specified period of time to meet immediate demand and position the line to meet tomorrow's demand. This paper will describe the approach used by IBM Burlington Advanced Industrial Engineering group which integrates various decision technologies using APL2 and OSL to generate a “daily output plan” for IBM's semiconductor facility near Burlington, VT.     

Color enhancement of highly correlated images. I. Decorrelation and HSI contrast stretches

Conventional enhancements for the color display of multispectral images are based on independent contrast modifications or “stretches” of three input images. This approach is not effective if the image channels are highly correlated or if the image histograms are strongly bimodal or more complex. Any of several procedures that tend to “stretch” color saturation while leaving hue unchanged may better utilize the full range of colors for the display of image information. Two conceptually different enhancements are discussed: the “decorrelation stretch”, based on principal-component (PC) analysis, and the “stretch” of “hue”-“saturation”-intensity (HSI) transformed data. The PC transformation is scene-dependent, but the HSI transformation is invariant. Examples of images enhanced by conventional linear stretches, decorrelation stretch, and by stretches of HSI transformed data are compared. Schematic variation diagrams or two- and three-dimensional histograms are used to illustrate the “decorrelation stretch” method and the effect of the different enhancements.     

Sketching space

In this paper, we present a sketch modelling system which we call Stilton. The program resembles a desktop VRML browser, allowing a user to navigate a three-dimensional model in a perspective projection, or panoramic photographs, which the program maps onto the scene as a “floor” and “walls”. We place an imaginary two-dimensional drawing plane in front of the user, and any geometric information that user sketches onto this plane may be reconstructed to form solid objects through an optimisation process. We show how the system can be used to reconstruct geometry from panoramic images, or to add new objects to an existing model. While panoramic imaging can greatly assist with some aspects of site familiarisation and qualitative assessment of a site, without the addition of some foreground geometry they offer only limited utility in a design context. Therefore, we suggest that the system may be of use in “just-in-time” CAD recovery of complex environments, such as shop floors, or construction sites, by recovering objects through sketched overlays, where other methods such as automatic line-retrieval may be impossible. The result of using the system in this manner is the “sketching of space” — sketching out a volume around the user — and once the geometry has been recovered, the designer is free to quickly sketch design ideas into the newly constructed context, or analyse the space around them. Although end-user trials have not, as yet, been undertaken we believe that this implementation may afford a user-interface that is both accessible and robust, and that the rapid growth of pen-computing devices will further stimulate activity in this area.