Showing papers on "Taguchi methods published in 1994"

A simple procedure for optimising the polymerase chain reaction (PCR) using modified Taguchi methods

Abstract: Taguchi methods are used widely as the basis for development trials during industrial process design. Here, we describe their suitability for optimisation of the PCR. Unlike conventional strategies, these arrays revealed the effects and interactions of specific reaction components simultaneously using just a few reactions, negating the need for extensive experimental investigation. Reaction components which effected product yield were easily determined. In addition, this technique was applied to the qualitative investigation of RAPD-PCR profiles, where optimisation of the size and distribution of a number of products was determined.

How to Achieve a Robust Process Using Response Surface Methodology

Abstract: Taguchi's experimental system is used to develop robust processes, that is, processes which are insensitive to variations in uncontrollable variables, such as environmental variables. Taguchi's recommended designs can be considered to be response surfac..

Taguchi Methods: A Hands-On Approach

Abstract: (1994). Taguchi Methods: A Hands-On Approach. Journal of Quality Technology: Vol. 26, No. 1, pp. 77-78.

Comparison of a full factorial experiment to fractional and Taguchi designs in a lathe dry turning operation

Abstract: This paper presents a comparison of three different experimental designs aimed at studying the effects of cutting parameters variations on surface finish. The results revealed that the effects obtained by analyzing both fractional and Taguchi designs (16 trials each) were comparable to the main effects and tow-level interactions obtained by the full factorial design (288 trials). Thus, we conclude that screening designs appear to be reliable and more economical since they permit to reduce by a factor 18 the amount of time and effort required to conduct the experimental design without losing valuable information.

The Taguchi influence on designed experiments

Abstract: This paper is intended to convey the essence of Taguchi's design approach to chemists and others with an interest in chemometrics. Although most Taguchi-style applications worldwide have been in electronics and in elaborately transformed manufactures, examples are increasingly found in chemical processes and in the food industry. Foremost among Taguchi's contributions is the concept of designing processes and products to be robust to the uncontrollable environmental influences which they experience during their operation or lifetime. This concept is explained with a worked example.

An economic design of [xbar] control chart using quadratic loss function

Abstract: The quadratic loss function is used in Taguchi's on-line cost model to estimate the quality cost. However, Taguchi's on-line quality control approach is different from the widely used statistical process control techniques where control charts are the primary tools for quality control. Duncan's economic design of x control chart is the first attempt to design the control charts in terms of process cost. In this paper, we present a new economic design based on the loss function approach as advocated by Taguchi. We also obtain the optimal parameters of the control chart that minimize the total quality cost.

Conceptual Robustness in Simultaneous Engineering: An Extension of Taguchi's Parameter Design

Abstract: Simultaneous engineering processes involve multifunctional teams; team members simultaneously make decisions about many parts of the product-production system and aspects of the product life cycle. This paper argues that such simultaneous distributed decisions should be based on communications about sets of possibilities rather than single solutions. By extending Taguchi's parameter design concepts, we develop a robust and distributed decision-making procedure based on such communications. The procedure shows how a member of a design team can make appropriate decisions based on incomplete information from the other members of the team. More specifically, it (1) treats variations among the designs considered by other members of the design team asconceptual noise; (2) shows how to incorporate such noises into decisions that are robust against these variations; (3) describes a method for using the same data to provide preference information back to the other team members; and (4) provides a procedure for determining whether to release theconceptually robust design or to wait for further decisions by others. The method is demonstrated by part of a distributed design process for a rotary CNC milling machine. While Taguchi's approach is used as a starting point because it is widely known, these results can be generalized to use other robust decision techniques.

Parameter design methodology for chemical processes using a simulator

Abstract: Parameter design is a method popularized by the Japanese quality expert G. Taguchi, for designing products and manufacturing processes that are robust in the face of uncontrollable variations. At the design stage, the goal of parameter design is to identify design settings that make the product performance less sensitive to the effects of manufacturing and environmental variations and deterioration. Because parameter design reduces performance variation by reducing the influence of the sources of variation rather than by controlling them, it is a cost-effective technique for improving quality. A recent study on the application of parameter design methodology for chemical processes reported that the use of Taguchi's method was not justified and a method based on Monte Carlo simulation combined with optimization was shown to be more effective. However, this method is computationally intensive as a large number of samples are necessary to achieve the given accuracy. Additionally, determination of the number of sample runs required is based on experimentation due to a lack of systematic sampling methods. In an attempt to overcome these problems, the use of a stochastic modeling capability combined with an optimizer is presented in this paper. The objective is that of providing an effective means for application of parameter design methodologies to chemical processes using the ASPEN simulator. This implementation not only presents a generalized tool for use by chemical engineers at large but also provides systematic estimates of the number of sample runs required to attain the specified accuracy. The stochastic model employs the technique of Latin hypercube sampling instead of the traditional Monte Carlo technique and hence has a great potential to reduce the required number of samples. The methodology is illustrated via an example problem of designing a chemical process.

Results of a Rocket-Based Combined-Cycle SSTO Design Using Parametric; MDO Methods

Abstract: This paper reports the results of the second phase of a research project to characterize and optimize the design of an advanced launch vehicle for human access to low earth orbit. The vehicle makes use of rocket-based combined-cycle (RBCC) propulsion — a concept combining operating modes of an ejector, ramjet, scramjet, and rocket in a single engine. This research builds on previous work focused on advanced multiple mode propulsion concepts and advanced conical acceleration-class single-stage-toorbit (SSTO) launch vehicles. Three systems level design variables of interest were optimized using multidisciplinary design optimization (MDO) techniques. Specifically, Taguchi’s method of robust design was used to identify a combination of variables that minimize the vehicle sensitivity to unpredictable changes in engine weights and performance. In addition, a second-order response surface method (RSM) was used to approximate the design space and predict the minimum dry weight vehicle. The optimized vehicle results (weights, dimensions, performance) are favorably compared with other SSTO designs including rocket and airbreathing concepts.

Design for Quality Using Response Surface Methods: An Alternative to Taguchi's Parameter Design Approach

Abstract: This article presents the response surface methodology as an alternative approach to Taguchi's parameter design methods for optimizing designs for quality The method is briefly explained, and its application is illustrated by an example of a preliminary design study of an advanced space transportation vehicle The results indicate that the response surface methodology is a systematic and efficient approach that can help engineering managers design for quality, performance, and cost

Structural Optimization Post-Process Using Taguchi Method

Abstract: A scheme for an application of the Taguchi method is suggested as a post process of the conventional structural optimization Design variables of the optimization are substituted by the factors of the Taguchi method If an optimum solution is calculated in the continuous space of design variables, an orthogonal array is constructed by the neighboring values of the optimum solution The neighboring values are determined form the available sizes in the design specifications which have discrete values By evaluating the orthogonal array and SN ratio, the final design is determined Unconstrained and constrained problems are solved for application examples

Making full use of taguchi's orthogonal arrays

Abstract: Taguchi1 has provided 18 orthogonal arrays which have been widely touted as useful frameworks for planning experiments. Thirteen of these are ‘saturated designs’, that is, they are appropriate for investigating (N - 1) factors in N runs, thus using the full capacity of the design. Here, the other five ‘non-saturated’ designs are discussed. By creating additional, orthogonal columns which provide estimates of interaction effects, we can essentially wring out some additional information over and above that suggested by Taguchi, without additional cost. In particular, if only the linear effect is of interest for any specific factor, one can accommodate more factors than the number suggested by Taguchi. An example is given for illustration.

Environmental stress screening experiment using the Taguchi method

Abstract: Manufacturing process improvements which increase productivity, decrease test process time, and improve customer satisfaction are highly desirable in today's marketplace. The application of environmental stress screening (ESS) is a method of achieving these improvements. ESS is the application of stresses applied beyond product specification limits in order to find latent product defects. Utilizing ESS achieves increased robustness and lower infant mortality. An experiment was performed to identify the significance or relevancy of the selected stresses for application in the printed wiring board (PWA) production process by using a statistically significant controlled method. The design of experiments statistical approach (analysis of variance), is applied, combined with the Taguchi two-level, seven-factor design method. This experiment concentrated on three stresses (temperature cycling, random vibration, and power cycling) and two diagnostic levels: a prom-based (programmable memory chip), power-on self test (POST), and a functional diagnostic test suite, contained on disk storage. Note that this was not an optimization experiment. Once the significance to the production process is identified, future optimizing of temperature cycling, power cycling, and vibration screens, will be conducted. Also, voltage margining was not included so as to reduce the complexity of the experiment-treatment factors and interactions. Experimental results and conclusions on the effectiveness of different stress regimens are presented in this paper. >

Interaction Graphs for Three-Level Fractional Factorial Designs

Abstract: Graph-aided methods for accommodating the estimation of interactions in factorial experiments have become popular among industrial users. Notable among them is the method of linear graphs due to Taguchi. Previously, some shortcomings of Taguchi's linear..

Robust design through optimization techniques

Abstract: Box and Fung have recommended that some robust design problems, such as those illustrated by Taguchi, can be solved more efficiently using nonlinear optimization techniques than Taguchi Methods. In this article, the use of nonlinear programming and dyna..

The Taguchi's performance statistic to optimize theophylline beads production in a high-speed granulator

Abstract: An original process using a simple procedure is developed to produce theophylline active pellets. In order to improve this process, an optimization approach is applied. But rather than only trying to bring the process to the target optimal values, attempt is made to find operating conditions leading also to stable and non-sensitive pellets characteristics. In this purpose, the classic experimental design approach and response surface methodology are completed by using Taguchi's philosophy.

Optimal process control in stamping operation

Abstract: The optimal process variables in producing stamping parts are determined for a door inner panel through the Taguchi L9 experimental design. The variables considered in this work are the inner tonnage, the outer tonnage, and the punch speed. The experime..

A Taguchi experimental design study of twin-wire electric arc sprayed aluminum coatings

Abstract: An experimental study was conducted on the twin-wire electric arc spraying of aluminum coatings. This aluminum wire system is being used to fabricate heater tubes that emulate nuclear fuel tubes for use in thermal-hydraulic experiments. Experiments were conducted using a Taguchi fractional-factorial design parametric study. Operating parameters were varied around the typical process parameters in a systematic design of experiments in order to display the range of processing conditions and their effect on the resultant coating. The coatings were characterized by hardness tests, optical metallography, and image analysis. The paper discusses coating qualities with respect to hardness, roughness, deposition efficiency, and microstructure. The study attempts to correlate the features of the coatings with the changes in operating parameters. A numerical model of the process is presented including gas, droplet, and coating dynamics.

A critique of the Taguchi approach. II: An alternative that is more efficient

Abstract: Part I of this paper (JCT, March 1994, page 65) showed that the Taguchi approach to experimental design and analysis has some serious deficiencies. A more efficient and powerful approach, which is free of these defects, is presented in this paper and is illustrated by re-examining a paper which recently appeared in this Journal in which the Taguchi approach was employed

A critique of the Taguchi approach. I: A presentation of some deficiencies and how these limit its efficiency and validity

Abstract: The emphasis in the Taguchi method of quality control, on using experimental design to improve the quality and performance of products and processes by designing them to be insensitive to noise factors, is viewed by many statisticians as his major contribution. The statistical tools he proposes to achieve this goal have been shown to be less efficient and more complicated than other existing methods. These alternative methods of analysis are recommended by some eminent statisticians as the preferred tools to analyze data from designed experiments

Optimizing the gas chromatographic separation and detection of polychlorinated biphenyls by use of electronic pressure programming and experimental design

Abstract: The applicability of electronic pressure control and Taguchi L27 experimental design to the optimization of the gas chromatographic separation and detection of polychlorinated biphenyls has been evaluated. The influence of several experimental variables, column temperature program, carrier gas pressure program, on-column injector temperature program, and make-up gas pressure program, was studied using analysis of variance. Simultaneous optimization of sample introduction, column efficiency, and detector performance could be achieved without compromising system performance. The relationships between system performance and experimental variables were established using regression analysis. Agreement between the simulated and experimental results obtained using suggested optimum conditions demonstrated the applicability of the technique developed in this study. The improvement achieved in the chromatographic separation of PCBs is presented.

Interactions: ignore them at your own risk ( how taguchps confirmation run strategy can lead to trouble)

Abstract: Genichi Taguchi's strategy for analyzing DOE interactions involves the use of saturated experimental designs, where interactions are not assigned to any columns of the array He suggests that the existence of interactions can be detected after the fact

Quality Up, Costs Down: A Manager's Guide to Taguchi Methods and Qfd

Abstract: (1996). Quality Up, Costs Down: A Manager's Guide to Taguchi Methods and QFD. Technometrics: Vol. 38, No. 2, pp. 183-184.

Application of the taguchi experimental design to the optimisation of a photo-oxidation procedure for trace metal analysis in freshwater

Abstract: A UV photo-oxidation device was constructed for the destruction of dissolved organic matter (DOM) in freshwater samples in order to determine traces of zinc, cadmium, lead and copper bound to DOM as inert species, by anodic stripping voltammetry in the differential pulse mode (DPASV). The photodigestor performance was optimised by means of the Taguchi experimental design. Four control factors (or design parameters) at three levels were explored: exposure-time to the UV-irradiation, pH of the sample, hydrogen peroxide concentration and mineral acid added, and assigned to the columns of a L9(34) saturated orthogonal array. A noise factor (nitrilotriacetic acid concentration) at three levels was introduced in the experiment to simulate the uncontrollable amount of DOM in water samples. The experiment was conducted with two replications of each trial and an optimum response insensitive to the variations of DOM concentration was found when samples, acidified at pH 2 with sulphuric acid, were irradiated for 30 min in the presence of 12.3 mmol/L hydrogen peroxide. The proposed procedure is more precise, accurate and fast than the wet digestion method.