Orthogonal Array Experiments and Response Surface Methodology

Total Page:16

File Type:pdf, Size:1020Kb

Orthogonal Array Experiments and Response Surface Methodology Unit 7: Orthogonal Array Experiments and Response Surface Methodology • A modern system of experimental design. • Orthogonal arrays (sections 8.1-8.2; appendix 8A and 8C). • Analysis of experiments with complex aliasing (part of sections 9.1-9.4). • Brief response surface methodology, central composite designs (sections 10.1-10.2). 1 Two Types of Fractional Factorial Designs • Regular (2n−k, 3n−k designs): columns of the design matrix form a group over a finite field; the interaction between any two columns is among the columns, ⇒ any two factorial effects are either orthogonal or fully aliased. • Nonregular (mixed-level designs, orthogonal arrays) some pairs of factorial effects can be partially aliased ⇒ more complex aliasing pattern. This includes 3n−k designs with linear-quadratic system. 2 A Modern System of Experimental Design It has four branches: • Regular orthogonal arrays (Fisher, Yates, Finney, ...): 2n−k, 3n−k designs, using minimum aberration criterion. • Nonregular orthogonal designs (Plackett-Burman, Rao, Bose): Plackett-Burman designs, orthogonal arrays. • Response surface designs (Box): fitting a parametric response surface. • Optimal designs (Kiefer): optimality driven by specific model/criterion. 3 Orthogonal Arrays • In Tables 1 and 2, the design used does not belong to the 2k−p series (Chapter 5) or the 3k−p series (Chapter 6), because the latter would require run size as a power of 2 or 3. These designs belong to the class of orthogonal arrays. m1 mγ • An orthogonal array array OA(N,s1 ...sγ ,t) of strength t is an N × m matrix, m = m1 + ... + mγ, in which mi columns have si(≥ 2) symbols or levels such that, for any t columns, all possible combinations of symbols appear equally often in the matrix. • For OA of strength two, the index t = 2 is dropped for simplicity. • An OA(12,211) is used in Table 1 and an OA(18,2137) is used in Table 2. 4 Example : OA(12,211) Table 1: Design Matrix and Lifetime Data, Cast Fatigue Experiment Factor Logged Run ABCDEFG 8 9 10 11 Lifetime 1 + + − + + + − − − + − 6.058 2 + − + + + − − − + − + 4.733 3 − + + + − − − + − + + 4.625 4 + + + − − − + − + + − 5.899 5 + + − − − + − + + − + 7.000 6 + − − − + − + + − + + 5.752 7 − − − + − + + − + + + 5.682 8 − − + − + + − + + + − 6.607 9 − + − + + − + + + − − 5.818 10 + − + + − + + + − − − 5.917 11 − + + − + + + − − − + 5.863 12 −−−−−−−−−−− 4.809 5 Example : OA(18,2137) Table 2: Design Matrix and Response Data, Blood Glucose Experiment Factor Mean Run AGBCDEFH Reading 1 00000000 97.94 2 00111111 83.40 3 00222222 95.88 4 01001122 88.86 5 01112200 106.58 6 01220011 89.57 7 02010212 91.98 8 02121020 98.41 9 02202101 87.56 10 10022110 88.11 11 10100221 83.81 12 10211002 98.27 13 11012021 115.52 14 11120102 94.89 15 11201210 94.70 16 12021201 121.62 17 12102012 93.86 18 12210120 96.10 6 Why Using Orthogonal Array • Run size economy. Suppose 8-11 factors at two levels are to be studied. Using an OA(12,211) will save 4 runs over a 16-run 2k−p design. Similarly, suppose 5-7 factors at three levels are to be studied. Using an OA(18,37) will save 9 runs over a 27-run 3k−p design. • Flexibility. Many OA’s exist for flexible combinations of factor levels. See the collection on next page. 7 A Result on Run Size of OA m1 mγ • Lemma. For an orthogonal array OA(N, s1 ···sγ , t), its run size N must γ ∏ ki be divisible by the least common multiple of i=1 si for all possible ∑γ γ combinations of ki with ki ≤ mi and i=1 ki = t, i = 1,..., . Its proof is given on p. 375 of WH. • Example of its use. Suppose an experimenter needs to find an OA(N, 2233) k k of strength two. Among 2 1 3 2 with k1 + k2 = 2, there are three possibilities: 22, 32, and 2 · 3. Its least common multiple is 4 × 9 = 36. Thus the minimal N value is 36. 8 Useful Orthogonal Arrays • Collection in Appendix 8A and 8C of WH: *OA(12,211) OA(12,3124) *OA(18,2137) OA(18,6136) OA(20,219) OA(24,31216) OA(24,61214) *OA(36,211312) OA(36,3763) OA(36,2863) OA(48,211412) OA(50,21511) OA(54,21325) * especially useful • Learn to choose and use the design tables in the collection. 9 OA(18,2137) and OA(18,6136) Table 3: OA(18,2137) (columns 1–8) and OA(18,6136) (columns 1′ and 3–8) Run 1′ 12345678 1 000000000 2 000111111 3 000222222 4 101001122 5 101112200 6 101220011 7 202010212 8 202121020 9 202202101 10 310022110 11 310100221 12 310211002 13 411012021 14 411120102 15 411201210 16 512021201 17 512102012 18 512210120 10 OA(36,211312) Table 4: OA(36,211312) Run 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 1 00000000000000000000000 2 00000000000111111111111 3 00000000000222222222222 4 00000111111000011112222 5 00000111111111122220000 6 00000111111222200001111 7 00111000111001201220112 8 00111000111112012001220 9 00111000111220120112001 10 01011011001002102121021 11 01011011001110210202102 12 01011011001221021010210 13 01101101010012021022101 14 01101101010120102100212 15 01101101010201210211020 16 01110110100012100212210 17 01110110100120211020021 18 01110110100201022101102 11 OA(36,211312) Table 4: Continued Run 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 19 10110011010010222011012 20 10110011010121000122120 21 10110011010202111200201 22 10101110001011220100221 23 10101110001122001211002 24 10101110001200112022110 25 10011101100021012202011 26 10011101100102120010122 27 10011101100210201121200 28 11100001101021110021202 29 11100001101102221102010 30 11100001101210002210121 31 11010100011022212110100 32 11010100011100020221211 33 11010100011211101002022 34 11001010110020121201120 35 11001010110101202012201 36 11001010110212010120012 12 Partial and Complex Aliasing • For the 12-run Plackett-Burman design OA(12,211) ˆ 1 E(βi)= βi + ∑ ±β jk 3 j,k= i 1 partial aliasing: coefficient ± 3 10 complex aliasing: 45(= 2 ) partial aliases • Traditionally complex aliasing was considered to be a disadvantage because it leads to many possible models which can be hard to discriminate. 13 Analysis Strategies • Traditionally experiments with complex aliasing were used for screening purpose, i.e., estimating main effects only • A paradigm shift: using effect sparsity/heredity, Hamada-Wu (1992) recognized that complex aliasing can be turned into an advantage for studying interactions • Analysis methods allow two-factor interactions to be entertained (in addition to main effects). Effective if the number of significant interactions is small. Frequentist method in Section 9.4 and Bayesian method in Section 9.5. 14 Traditional Approach: Main Effect Analysis · F · D · · absolute constrasts · A · B · · C · G · E · 0 1 2 3 4 5 6 0.0 0.5 1.0 1.5 2.0 2.5 half-normal quantiles Figure 1: Half-normal plot, cast fatigue experiment. • Only factor F is significant (R2 = 0.45). Adding the next effect D gives R2 = 0.59, a marginal improvement. 15 Complex Aliasing • Consider the cast fatigue experiment. Let the main effect estimate of factor A be Aˆ = y¯(A = +) − y¯(A = −), etc. • Assuming no 3fi’s or higher, it can be shown that 1 1 1 1 1 E(Aˆ)= A − BC − BD − BE + BF − BG 3 3 3 3 3 1 1 1 1 1 + CD − CE − CF + CG + DE 3 3 3 3 3 1 1 1 1 1 + DF − DG − EF − EG − FG, 3 3 3 3 3 1 1 1 1 1 E(Bˆ)= B − AC − AD − AE + AF − AG 3 3 3 3 3 1 1 1 1 1 − CD − CE − CF + CG + DE 3 3 3 3 3 1 1 1 1 1 − DF − DG + EF + EG − FG, 3 3 3 3 3 • Similar complex equations for Cˆ, Dˆ , Eˆ, Fˆ, Gˆ. This relationship is called complex aliasing. 16 Complex Aliasing Simplified by Effect Sparsity • For the cast fatigue experiment, suppose the true (but unknown) significant effects are A, F, G, AB and FG, which can be justified by effect sparsity. Then the relationships are simplified: 1 E(Aˆ) = A − FG, 3 1 E(Bˆ) = − FG, 3 1 1 E(Cˆ) = − AB + FG, 3 3 1 1 E(Dˆ ) = − AB + FG, 3 3 1 1 E(Eˆ) = − AB − FG, 3 3 1 E(Fˆ) = F + AB, 3 1 E(Gˆ) = G − AB, 3 suggesting the viability of estimating significant main effects and 2fi’s. 17 Hamada-Wu Analysis Strategy 1. For each factor X, consider X and all 2fi’s XY involving X. Use stepwise regression to identify significant effects. Repeat this for each X and keep the best model. 2. Use stepwise regression to identify significant effects among effects identified in 1 and the main effects. 3. Using effect heredity, consider (i) effects identified in 2 and (ii) 2fi’s with at least one parent factor appearing in the main effects in (i). Use stepwise regression to identify significant effects. 4. Iterate between 2 and 3 until model stops changing. 18 Analysis of Cast Fatigue Experiment • Since F is significant in the main effect analysis, consider 2fi’s involving F. This leads to FG and R2 is increased to 0.89, almost doubled! • A better prediction based on yˆ = 5.7 + 0.458F − 0.459FG. By choosing G− and F+, predicted life is 5.7 + 0.458 − 0.459(−1)= 5.7 + 0.92 = 6.62, 0.92 a 16% increase (= 5.7 ) over the main effect model with F only. 19 Summary of Analysis Results • Cast Fatigue Experiment: Main effect analysis : F (R2 = 0.45) F, D (R2 = 0.59) HW analysis : F, FG (R2 = 0.89) F, FG, D (R2 = 0.92) • Blood Glucose Experiment: 2 Main effect analysis : Eq, Fq (R = 0.36) 2 HW analysis : Bl, (BH)lq, (BH)qq (R = 0.89) 20 Poorman’s Response Surface Methodology • Consider an experiment to study three quantitative factors with up to 5 levels.
Recommended publications
  • Orthogonal Arrays and Row-Column and Block Designs for CDC Systems
    Current Trends on Biostatistics & L UPINE PUBLISHERS Biometrics Open Access DOI: 10.32474/CTBB.2018.01.000103 ISSN: 2644-1381 Review Article Orthogonal Arrays and Row-Column and Block Designs for CDC Systems Mahndra Kumar Sharma* and Mekonnen Tadesse Department of Statistics, Addis Ababa University, Addis Ababa, Ethiopia Received: September 06, 2018; Published: September 20, 2018 *Corresponding author: Mahndra Kumar Sharma, Department of Statistics, Addis Ababa University, Addis Ababa, Ethiopia Abstract In this article, block and row-column designs for genetic crosses such as Complete diallel cross system using orthogonal arrays (p2, r, p, 2), where p is prime or a power of prime and semi balanced arrays (p(p-1)/2, p, p, 2), where p is a prime or power of an odd columnprime, are designs derived. for Themethod block A designsand C are and new row-column and consume designs minimum for Griffing’s experimental methods units. A and According B are found to Guptato be A-optimalblock designs and thefor block designs for Griffing’s methods C and D are found to be universally optimal in the sense of Kiefer. The derived block and row- Keywords:Griffing’s methods Orthogonal A,B,C Array;and D areSemi-balanced orthogonally Array; blocked Complete designs. diallel AMS Cross; classification: Row-Column 62K05. Design; Optimality Introduction d) one set of F ’s hybrid but neither parents nor reciprocals Orthogonal arrays of strength d were introduced and applied 1 F ’s hybrid is included (v = 1/2p(p-1). The problem of generating in the construction of confounded symmetrical and asymmetrical 1 optimal mating designs for CDC method D has been investigated factorial designs, multifactorial designs (fractional replication) by several authors Singh, Gupta, and Parsad [10].
    [Show full text]
  • Latin Squares in Experimental Design
    Latin Squares in Experimental Design Lei Gao Michigan State University December 10, 2005 Abstract: For the past three decades, Latin Squares techniques have been widely used in many statistical applications. Much effort has been devoted to Latin Square Design. In this paper, I introduce the mathematical properties of Latin squares and the application of Latin squares in experimental design. Some examples and SAS codes are provided that illustrates these methods. Work done in partial fulfillment of the requirements of Michigan State University MTH 880 advised by Professor J. Hall. 1 Index Index ............................................................................................................................... 2 1. Introduction................................................................................................................. 3 1.1 Latin square........................................................................................................... 3 1.2 Orthogonal array representation ........................................................................... 3 1.3 Equivalence classes of Latin squares.................................................................... 3 2. Latin Square Design.................................................................................................... 4 2.1 Latin square design ............................................................................................... 4 2.2 Pros and cons of Latin square design...................................................................
    [Show full text]
  • Orthogonal Array Application for Optimized Software Testing
    WSEAS TRANSACTIONS on COMPUTERS Ljubomir Lazic and Nikos Mastorakis Orthogonal Array application for optimal combination of software defect detection techniques choices LJUBOMIR LAZICa, NIKOS MASTORAKISb aTechnical Faculty, University of Novi Pazar Vuka Karadžića bb, 36300 Novi Pazar, SERBIA [email protected] http://www.np.ac.yu bMilitary Institutions of University Education, Hellenic Naval Academy Terma Hatzikyriakou, 18539, Piraeu, Greece [email protected] Abstract: - In this paper, we consider a problem that arises in black box testing: generating small test suites (i.e., sets of test cases) where the combinations that have to be covered are specified by input-output parameter relationships of a software system. That is, we only consider combinations of input parameters that affect an output parameter, and we do not assume that the input parameters have the same number of values. To solve this problem, we propose interaction testing, particularly an Orthogonal Array Testing Strategy (OATS) as a systematic, statistical way of testing pair-wise interactions. In software testing process (STP), it provides a natural mechanism for testing systems to be deployed on a variety of hardware and software configurations. The combinatorial approach to software testing uses models to generate a minimal number of test inputs so that selected combinations of input values are covered. The most common coverage criteria are two-way or pairwise coverage of value combinations, though for higher confidence three-way or higher coverage may be required. This paper presents some examples of software-system test requirements and corresponding models for applying the combinatorial approach to those test requirements. The method bridges contributions from mathematics, design of experiments, software test, and algorithms for application to usability testing.
    [Show full text]
  • Generating and Improving Orthogonal Designs by Using Mixed Integer Programming
    European Journal of Operational Research 215 (2011) 629–638 Contents lists available at ScienceDirect European Journal of Operational Research journal homepage: www.elsevier.com/locate/ejor Stochastics and Statistics Generating and improving orthogonal designs by using mixed integer programming a, b a a Hélcio Vieira Jr. ⇑, Susan Sanchez , Karl Heinz Kienitz , Mischel Carmen Neyra Belderrain a Technological Institute of Aeronautics, Praça Marechal Eduardo Gomes, 50, 12228-900, São José dos Campos, Brazil b Naval Postgraduate School, 1 University Circle, Monterey, CA, USA article info abstract Article history: Analysts faced with conducting experiments involving quantitative factors have a variety of potential Received 22 November 2010 designs in their portfolio. However, in many experimental settings involving discrete-valued factors (par- Accepted 4 July 2011 ticularly if the factors do not all have the same number of levels), none of these designs are suitable. Available online 13 July 2011 In this paper, we present a mixed integer programming (MIP) method that is suitable for constructing orthogonal designs, or improving existing orthogonal arrays, for experiments involving quantitative fac- Keywords: tors with limited numbers of levels of interest. Our formulation makes use of a novel linearization of the Orthogonal design creation correlation calculation. Design of experiments The orthogonal designs we construct do not satisfy the definition of an orthogonal array, so we do not Statistics advocate their use for qualitative factors. However, they do allow analysts to study, without sacrificing balance or orthogonality, a greater number of quantitative factors than it is possible to do with orthog- onal arrays which have the same number of runs.
    [Show full text]
  • Orthogonal Array Sampling for Monte Carlo Rendering
    Eurographics Symposium on Rendering 2019 Volume 38 (2019), Number 4 T. Boubekeur and P. Sen (Guest Editors) Orthogonal Array Sampling for Monte Carlo Rendering Wojciech Jarosz1 Afnan Enayet1 Andrew Kensler2 Charlie Kilpatrick2 Per Christensen2 1Dartmouth College 2Pixar Animation Studios (a) Jittered 2D projections (b) Multi-Jittered 2D projections (c) (Correlated) Multi-Jittered 2D projections wy wu wv wy wu wv wy wu wv y wx wx wx u wy wy wy v wu wu wu x y u x y u x y u Figure 1: We create high-dimensional samples which simultaneously stratify all bivariate projections, here shown for a set of 25 4D samples, along with their six stratified 2D projections and expected power spectra. We can achieve 2D jittered stratifications (a), optionally with stratified 1D (multi-jittered) projections (b). We can further improve stratification using correlated multi-jittered (c) offsets for primary dimension pairs (xy and uv) while maintaining multi-jittered properties for cross dimension pairs (xu, xv, yu, yv). In contrast to random padding, which degrades to white noise or Latin hypercube sampling in cross dimensional projections (cf. Fig.2), we maintain high-quality stratification and spectral properties in all 2D projections. Abstract We generalize N-rooks, jittered, and (correlated) multi-jittered sampling to higher dimensions by importing and improving upon a class of techniques called orthogonal arrays from the statistics literature. Renderers typically combine or “pad” a collection of lower-dimensional (e.g. 2D and 1D) stratified patterns to form higher-dimensional samples for integration. This maintains stratification in the original dimension pairs, but looses it for all other dimension pairs.
    [Show full text]
  • Association Schemes for Ordered Orthogonal Arrays and (T, M, S)-Nets W
    Canad. J. Math. Vol. 51 (2), 1999 pp. 326–346 Association Schemes for Ordered Orthogonal Arrays and (T, M, S)-Nets W. J. Martin and D. R. Stinson Abstract. In an earlier paper [10], we studied a generalized Rao bound for ordered orthogonal arrays and (T, M, S)-nets. In this paper, we extend this to a coding-theoretic approach to ordered orthogonal arrays. Using a certain association scheme, we prove a MacWilliams-type theorem for linear ordered orthogonal arrays and linear ordered codes as well as a linear programming bound for the general case. We include some tables which compare this bound against two previously known bounds for ordered orthogonal arrays. Finally we show that, for even strength, the LP bound is always at least as strong as the generalized Rao bound. 1 Association Schemes In 1967, Sobol’ introduced an important family of low discrepancy point sets in the unit cube [0, 1)S. These are useful for quasi-Monte Carlo methods such as numerical inte- gration. In 1987, Niederreiter [13] significantly generalized this concept by introducing (T, M, S)-nets, which have received considerable attention in recent literature (see [3] for a survey). In [7], Lawrence gave a combinatorial characterization of (T, M, S)-nets in terms of objects he called generalized orthogonal arrays. Independently, and at about the same time, Schmid defined ordered orthogonal arrays in his 1995 thesis [15] and proved that (T, M, S)-nets can be characterized as (equivalent to) a subclass of these objects. Not sur- prisingly, generalized orthogonal arrays and ordered orthogonal arrays are closely related.
    [Show full text]
  • 14.5 ORTHOGONAL ARRAYS (Updated Spring 2003)
    14.5 ORTHOGONAL ARRAYS (Updated Spring 2003) Orthogonal Arrays (often referred to Taguchi Methods) are often employed in industrial experiments to study the effect of several control factors. Popularized by G. Taguchi. Other Taguchi contributions include: • Model of the Engineering Design Process • Robust Design Principle • Efforts to push quality upstream into the engineering design process An orthogonal array is a type of experiment where the columns for the independent variables are “orthogonal” to one another. Benefits: 1. Conclusions valid over the entire region spanned by the control factors and their settings 2. Large saving in the experimental effort 3. Analysis is easy To define an orthogonal array, one must identify: 1. Number of factors to be studied 2. Levels for each factor 3. The specific 2-factor interactions to be estimated 4. The special difficulties that would be encountered in running the experiment We know that with two-level full factorial experiments, we can estimate variable interactions. When two-level fractional factorial designs are used, we begin to confound our interactions, and often lose the ability to obtain unconfused estimates of main and interaction effects. We have also seen that if the generators are choosen carefully then knowledge of lower order interactions can be obtained under that assumption that higher order interactions are negligible. Orthogonal arrays are highly fractionated factorial designs. The information they provide is a function of two things • the nature of confounding • assumptions about the physical system. Before proceeding further with a closer look, let’s look at an example where orthogonal arrays have been employed. Example taken from students of Alice Agogino at UC-Berkeley A Airplane Taguchi Experiment This experiment has 4 variables at 3 different settings.
    [Show full text]
  • Some Aspects of Design of Experiments
    Some Aspects of Design of Experiments Nancy Reid University of Toronto, Toronto Canada Abstract This paper provides a brief introduction to some aspects of the theory of design of experiments that may be relevant for high energy physics experiments and associated Monte Carlo investigations. 1 Introduction `Design of experiments' means something specific in the statistical literature, which is different from its more general use in science. The key notion is that there is an intervention applied to a number of experimental units; these interventions are conventionally called treatments. The treatments are usually assigned to experimental units using a randomization scheme, and randomization is taken to be a key element in the concept in the study of design of experiments. The goal is then to measure one or more responses of the units, usually with the goal of comparing the responses under the various treatments. Be- cause the intervention is under the control of the experimenter, a designed experiment generally provides a stronger basis for making conclusions on how the treatment affects the response than an observational study. The original area of application was agriculture, and the main ideas behind design of experiments, including the very important notion of randomization, were developed by Fisher at the Rothamsted Agri- cultural Station, in the early years of the twentieth century. A typical agricultural example has as exper- imental units some plots of land, as treatments some type of intervention, such as amount of or type of fertilizer, and as primary response yield of a certain crop. The theory of design of experiments is widely used in industrial and technological settings, where the experimental units may be, for example, man- ufactured objects of some type, such as silicon wafers, the treatments would be various manufacturing settings, such as temperature of an oven, concentration of an etching acid, and so on, and the response would be some measure of the quality of the resulting object.
    [Show full text]
  • Robust Parameter Design of Derivative Optimization Methods for Image Acquisition Using a Color Mixer †
    Journal of Imaging Article Robust Parameter Design of Derivative Optimization Methods for Image Acquisition Using a Color Mixer † HyungTae Kim 1,*, KyeongYong Cho 2, Jongseok Kim1, KyungChan Jin 1 and SeungTaek Kim 1 1 Smart Manufacturing Technology Group, KITECH, 89 Yangdae-Giro RD., CheonAn 31056, ChungNam, Korea; [email protected] (J.K.); [email protected] (K.J.); [email protected] (S.K.) 2 UTRC, KAIST, 23, GuSung, YouSung, DaeJeon 305-701, Korea; [email protected] * Correspondence: [email protected]; Tel.: +82-41-589-8478 † This paper is an extended version of the paper published in Kim, HyungTae, KyeongYong Cho, SeungTaek Kim, Jongseok Kim, KyungChan Jin, SungHo Lee. “Rapid Automatic Lighting Control of a Mixed Light Source for Image Acquisition using Derivative Optimum Search Methods.” In MATEC Web of Conferences, Volume 32, EDP Sciences, 2015. Received: 27 May 2017; Accepted: 15 July 2017; Published: 21 July 2017 Abstract: A tuning method was proposed for automatic lighting (auto-lighting) algorithms derived from the steepest descent and conjugate gradient methods. The auto-lighting algorithms maximize the image quality of industrial machine vision by adjusting multiple-color light emitting diodes (LEDs)—usually called color mixers. Searching for the driving condition for achieving maximum sharpness influences image quality. In most inspection systems, a single-color light source is used, and an equal step search (ESS) is employed to determine the maximum image quality. However, in the case of multiple color LEDs, the number of iterations becomes large, which is time-consuming. Hence, the steepest descent (STD) and conjugate gradient methods (CJG) were applied to reduce the searching time for achieving maximum image quality.
    [Show full text]
  • Robust Product Design: a Modern View of Quality Engineering in Manufacturing Systems
    Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 26 July 2018 doi:10.20944/preprints201807.0517.v1 Robust Product Design: A Modern View of Quality Engineering in Manufacturing Systems Amir Parnianifarda1, A.S. Azfanizama, M.K.A. Ariffina, M.I.S. Ismaila a. Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. ABSTRACT: One of the main technological and economic challenges for an engineer is designing high-quality products in manufacturing processes. Most of these processes involve a large number of variables included the setting of controllable (design) and uncontrollable (noise) variables. Robust Design (RD) method uses a collection of mathematical and statistical tools to study a large number of variables in the process with a minimum value of computational cost. Robust design method tries to make high-quality products according to customers’ viewpoints with an acceptable profit margin. This paper aims to provide a brief up-to-date review of the latest development of RD method particularly applied in manufacturing systems. The basic concepts of the quality loss function, orthogonal array, and crossed array design are explained. According to robust design approach, two classifications are presented, first for different types of factors, and second for different types of data. This classification plays an important role in determining the number of necessity replications for experiments and choose the best method for analyzing data. In addition, the combination of RD method with some other optimization methods applied in designing and optimizing of processes are discussed. KEYWORDS: Robust Design, Taguchi Method, Product Design, Manufacturing Systems, Quality Engineering, Quality Loss Function.
    [Show full text]
  • Matrix Experiments Using Orthogonal Arrays
    Matrix Experiments Using Orthogonal Arrays Robust System Design 16.881 MIT Comments on HW#2 and Quiz #1 Questions on the Reading Quiz Brief Lecture Paper Helicopter Experiment Robust System Design 16.881 MIT Learning Objectives • Introduce the concept of matrix experiments • Define the balancing property and orthogonality • Explain how to analyze data from matrix experiments • Get some practice conducting a matrix experiment Robust System Design 16.881 MIT Static Parameter Design and the P-Diagram Noise Factors Induce noise Product / Process Signal Factor Response Hold constant Optimize for a “static” Control Factors experiment Vary according to an experimental plan Robust System Design 16.881 MIT Parameter Design Problem • Define a set of control factors (A,B,C…) • Each factor has a set of discrete levels • Some desired response η (A,B,C…) is to be maximized Robust System Design 16.881 MIT Full Factorial Approach • Try all combinations of all levels of the factors (A1B1C1, A1B1C2,...) • If no experimental error, it is guaranteed to find maximum • If there is experimental error, replications will allow increased certainty • BUT ... #experiments = #levels#control factors Robust System Design 16.881 MIT Additive Model • Assume each parameter affects the response independently of the others η( Ai , B j , Ck , Di ) = µ + ai + b j + ck + di + e • This is similar to a Taylor series expansion ∂f ∂f f (x, y) = f (xo , yo ) + ⋅ (x − xo ) + ⋅ ( y − yo ) + h.o.t ∂x x= x ∂y o y = yo Robust System Design 16.881 MIT One Factor at a Time Control Factors Expt. A B C D No.
    [Show full text]
  • Package 'Doe.Base'
    Package ‘DoE.base’ September 2, 2021 Title Full Factorials, Orthogonal Arrays and Base Utilities for DoE Packages Version 1.2 Depends R (>= 2.10), grid, conf.design Imports stats, utils, graphics, grDevices, vcd, combinat, MASS, lattice, numbers, partitions Suggests FrF2, DoE.wrapper, RColorBrewer Date 2021-09-01 Description Creates full factorial experimental designs and designs based on orthogonal ar- rays for (industrial) experiments. Provides diverse quality criteria. Provides utility func- tions for the class design, which is also used by other packages for designed experiments. License GPL (>= 2) LazyLoad yes LazyData yes Encoding latin1 URL https://prof.beuth-hochschule.de/groemping/DoE/, https://prof.beuth-hochschule.de/groemping/ NeedsCompilation no Maintainer Ulrike Groemping <[email protected]> Author Ulrike Groemping [aut, cre], Boyko Amarov [ctb], Hongquan Xu [ctb] Repository CRAN Date/Publication 2021-09-02 15:50:05 UTC R topics documented: DoE.base-package . .2 add.response . .4 block.catlg3 . .6 1 2 DoE.base-package Class design and accessors . .7 contr.FrF2 . 12 corrPlot . 13 cross.design . 16 expansive.replace . 19 export.design . 20 fac.design . 23 factorize . 28 formula.design . 29 genChild . 31 generalized.word.length . 32 getblock . 41 GRind . 43 halfnormal . 47 ICFTs . 52 iscube . 55 lm and aov method for class design objects . 56 lowerbound_AR . 61 Methods for class design objects . 63 oa.design . 67 oacat . 74 oa_feasible . 77 param.design . 80 planor2design . 82 Plotting class design objects . 83 print.oa . 87 qua.design . 88 Reshape designs with repeated measurements . 90 show.oas . 92 SN.............................................. 95 VSGFS . 96 Index 100 DoE.base-package Full factorials, orthogonal arrays and base utilities for DoE packages Description This package creates full factorial designs and designs from orthogonal arrays.
    [Show full text]