Delbert L. Kimbler

An integrated joint optimization procedure for robust and tolerance design

Many manufacturers have discovered that optimizing design parameters is a costeffective means of improving product quality and being competitive in the world market. In this regard, the issues of robust design (RD) and tolerance design (TD) are clearly important, but there is significant room for improvement. The primary objective of this paper is to propose a set of enhanced optimization strategies by combining RD and TD. To be more specific, first, we consider an alternative experimental scheme using response surface methodology, while avoiding the use of controversial tools for RD such as orthogonal arrays and signal-to-noise ratios. Secondly, we discuss an enhanced optimization model by simultaneously considering both the process mean and variance, and then show that this model provides a better (or at least equal) solution in terms of the control factor settings. Thirdly, we show how the response functions for the process mean and variance, which are estimated by using an RD principle, are transmitted into the TD stage. Fourthly, we propose an optimization model for TD and present closed-form solutions for optimum tolerance limits. Finally, we study the possible effects of major cost components, and observe the behaviour of the optimum control parameter settings and the tolerance limits by carrying out sensitivity analysis.

The use of advanced technology for visual inspection training

In the past, training with traditional methods was shown to improve inspection performance. However, advances in technology have automated training and revolutionized the way training will be delivered in the future. Examples of such technology include computer-based simulators, digital interactive video, computer-based training, and intelligent tutoring systems. Despite the lower cost and increased availability of computer technology, the application of advanced technology to training within the manufacturing industry and specifically for inspection has been limited. In this vein, a case study is presented which shows how advanced technology along with our basic knowledge of training principles, can be used to develop a computer-based training program for a contact lens inspection task. Improvements due to computer-based inspection training were measured in an evaluation study and are reported.

Hospital evacuation: issues and complexities

Hospital evacuation is a difficult process that requires a robust strategy and careful execution. In the past, threats leading to possible evacuation were primarily natural disasters. In recent years the broadened nature of threats, including hazardous material spills and terrorist incidents, has complicated this already complex problem. Its importance continues to grow, but there is still no consistent approach to tackle this problem. Plan development and evaluation are crucial to the plans refinement which leads to successful response when an evacuation threat occurs. This research describes the issues inherent in planning and evaluation along with the complexities of constructing appropriate models for emergency preparedness and evacuation.

DEVELOPMENT OF THE OPTIMUM PRODUCT SPECIFICATION FOR AN EXPONENTIAL-TYPE QUALITY CHARACTERISTIC

This paper investigates the problem of determining the most economical product specification (upper specification limit) for an exponential-type quality characteristic using the concept of a truncated quadratic loss function within the framework of a screening inspection scheme. Implementing a tight limit on products may provide a high outgoing quality, but it creates a high rejection cost on the rejected products. In contrast, implementing a loose limit may reduce the rejection cost, but it can result in a low outgoing quality. An immediate problem is then how to trade off these conflicting cost criteria to determine the most economical upper specification limit. This important issue has neither been satisfactorily addressed or received much attention in the literature. This paper presents the concept of the truncated quadratic loss function, applies the concept to screening inspection problems, derives the truncated statistics of interest, and presents the optimization model of the most economical upper specification limit for an exponential-type quality characteristic. A numerical example is presented.

Compensating for Inspection Errors in Attribute Inspection

Sampling plans developed for attribute inspection have been designed based on the assumption that inspection is error-free or constant. Studies have shown that inspection is not error-free and is systematically influenced by such factors as time availab..

Process and quality control issues in the automated manufacturing of discrete parts

Abstract The techniques of quality control have been developed over a number of decades, during which the technology of manufacturing was essentially static in terms of control and strategy. Advances within the past decade have led to substantial changes in the manufacturing environment. Changes in the extent, type, and breadth of application of automation call into question some of the basic assumptions of classical quality control. Changes in the mode of manufacturing, such as JIT and emphasis on smaller lot sizes, raise further questions as to the validity of classical quality control in the modern manufacturing environment. This paper addresses some of the questions raised by recent advances in manufacturing and identifies issues for research in quality and process control in the modern manufacturing.

An Industrial Engineering Curriculum Renewal Process for the Enhancement of Industrial Engineering Degree Programs

The current Industrial Engineering curriculum implemented at most educational institutions in the United States is driven by curriculum reform included in the Roy Report which took place almost 40 years ago. It is clear that if Industrial Engineers are to keep pace with the changing environment we need to address the future of Industrial Engineering curriculum. In response, this paper outlines the development of a new scalable and deployable Industrial Engineering baccalaureate-degree curriculum renewal process. This model will be designed to permit scaling up from an information technology course kernel to a fully integrated Industrial Engineering undergraduate curriculum.

A Profit-Based Model Allowing for Quality Achievement and Manufacturing Process Selection

A model is proposed which provides a starting point for analyzing quality and process selection from a profit perspective. The model focuses on increased revenues rather than costs, and defines the level of quality to attain and how that goal may b..

Integration of interim quality status information in discrete-part process control modelling

Abstract This paper deals with the modelling of a class of discrete-part production control problems that explicitly joins product quality with optimal production control actions. A multistage production system is the basis for modelling, each stage consisting of a processing aspect and a rework/repair aspect. It is assumed that the “quality state” of a part can be measured with certainty at several points within each stage and that control actions can be exercised over each aspect. The state transition function depends on the control action taken and follows a predetermined distribution. Within this general framework, two related problems are studied: (1) independence both stage-to-stage and between states and (2) independence only between states. Both problems can be formulated in a {0, 1} nonlinear mathematical programming format, and numerical examples of each are provided.

Application of Advanced Technology to Training for Visual Inspection

Automation in the manufacturing industry has changed the nature of tasks from ones having large motor components to ones that have significant cognitive components. For example, several complex inspection tasks which exist in modern industry involve significant cognitive, decision making and recognition skills. Often workers are not adequately equipped to perform these tasks imposed by the new manufacturing environment. Thus, while the demands of modern manufacturing may be increasing, workers’ skills on the shop floor may in fact be diminishing. Training is the natural response to close this gap between task demands and worker skills. This paper reviews the principles of training and deduces their relevance to training for visual inspection. An example of use of these principles in developing a computer-based training program for visual inspection is given. Finally, the paper reports a study to support the application of advanced technology to visual inspection training for contact lens inspection.