University of Missouri-Columbia IMSE 8110 Engineering Experimentation Homework: Chapter 8 and Handout Problems Sergio García 909242 Melissa Rios 931546 Sumit Tayal 880581 November 15, 2004 Problems from photocopies of unknown book pages 168-177 5.2 A 25III2 design with generators I = 1234 = 135 is run a) If it is known that factors 1, 2, and 3 all act independently of one another, and that factors 3, 4, and 5 all act independently of one another, what (ignoring interactions of three or more factors) can we estimate? b) Can you suggest a better 25III2 design for these factors, or is it the given the best available? SOLUTION a) The design of this problem is a subset of the following original 2 5 factorial design: RUN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 2 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 3 -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 1 1 1 1 4 -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1 1 1 1 1 5 Treatment RUN 1 2 3 4 5 Treatment -1 I 17 -1 -1 -1 -1 1 5 -1 1 18 1 -1 -1 -1 1 15 -1 2 19 -1 1 -1 -1 1 25 -1 12 20 1 1 -1 -1 1 125 -1 3 21 -1 -1 1 -1 1 35 -1 13 22 1 -1 1 -1 1 135 -1 23 23 -1 1 1 -1 1 235 -1 123 24 1 1 1 -1 1 1235 -1 4 25 -1 -1 -1 1 1 45 -1 14 26 1 -1 -1 1 1 145 -1 24 27 -1 1 -1 1 1 245 -1 124 28 1 1 -1 1 1 1245 -1 34 29 -1 -1 1 1 1 345 -1 123 30 1 -1 1 1 1 1345 -1 234 31 -1 1 1 1 1 2345 -1 1234 32 1 1 1 1 1 12345 If we highlight the treatment combinations for what the generator is true, we obtain the following table: 1 5 32 2 8 treatment combinatio ns 4 4 I 1234 I 1 35 2 5III 2 4 123 RUN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 2 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 3 -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 1 1 1 1 4 -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1 1 1 1 1 5 13 5 Treatment RUN 1 2 3 4 5 Treatment -1 I 17 -1 -1 -1 -1 1 5 -1 1 18 1 -1 -1 -1 1 15 -1 2 19 -1 1 -1 -1 1 25 -1 12 20 1 1 -1 -1 1 125 -1 3 21 -1 -1 1 -1 1 35 -1 13 22 1 -1 1 -1 1 135 -1 23 23 -1 1 1 -1 1 235 -1 123 24 1 1 1 -1 1 1235 -1 4 25 -1 -1 -1 1 1 45 -1 14 26 1 -1 -1 1 1 145 -1 24 27 -1 1 -1 1 1 245 -1 124 28 1 1 -1 1 1 1245 -1 34 29 -1 -1 1 1 1 345 -1 134 30 1 -1 1 1 1 1345 -1 234 31 -1 1 1 1 1 2345 -1 1234 32 1 1 1 1 1 12345 We discard the treatment combinations that do not meet the required condition to obtain the following eight runs RUN 1 2 3 4 5 6 7 8 1 -1 1 -1 1 -1 1 -1 1 2 -1 -1 1 1 -1 -1 1 1 3 4 = 123 5 = 13 Treatment -1 -1 1 5 -1 1 -1 14 -1 1 1 245 -1 -1 -1 12 1 1 -1 34 1 -1 1 135 1 -1 -1 23 1 1 1 12345 It is known that factors 1, 2, and 3 all act independently of one another, and that factors 3, 4, and 5 all act independently of one another This means that the following treatment combinations are not necessary to carry out because the factors are independent from each other: 12 34 23 The only runs that shall be carried out are shown in the following table RUN 1 2 3 4 5 1 -1 1 -1 1 1 2 -1 -1 1 -1 1 3 4 = 123 5 = 13 Treatment -1 -1 1 5 -1 1 -1 14 -1 1 1 245 1 -1 1 135 1 1 1 12345 b) Eliminating those treatment combinations that are useless because of the independence of 1, 2,and 3 and 3, 4, and 5 from each other respectively we can choose a better design 2 5III 2 RUN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 2 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 3 -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 1 1 1 1 4 -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1 1 1 1 1 5 Treatment RUN 1 2 3 4 5 Treatment -1 I 17 -1 -1 -1 -1 1 5 -1 1 18 1 -1 -1 -1 1 15 -1 2 19 -1 1 -1 -1 1 25 -1 12 20 1 1 -1 -1 1 125 -1 3 21 -1 -1 1 -1 1 35 -1 13 22 1 -1 1 -1 1 135 -1 23 23 -1 1 1 -1 1 235 -1 123 24 1 1 1 -1 1 1235 -1 4 25 -1 -1 -1 1 1 45 -1 14 26 1 -1 -1 1 1 145 -1 24 27 -1 1 -1 1 1 245 -1 124 28 1 1 -1 1 1 1245 -1 34 29 -1 -1 1 1 1 345 -1 134 30 1 -1 1 1 1 1345 -1 234 31 -1 1 1 1 1 2345 -1 1234 32 1 1 1 1 1 12345 5.15 Identify the design given in Table E5.15 and perform an appropriate analysis. Assume V(yi) = σ2 = 2. What factors appear to influence the response? What features need to be further elucidated? If you were allowed to perform more runs, what would they be? Why? x1 1 -1 -1 -1 1 1 1 -1 x2 -1 1 -1 -1 1 1 -1 1 x3 -1 -1 1 -1 1 -1 1 1 x4 -1 -1 -1 1 -1 1 1 1 y 105 107 102 104 114 111 105 107 Solution Since we have 4 factors the total number of treatments for the complete 2 4 factorial design should be sixteen. We observe only eight in the fractional design. This means that this is a one-half fraction factorial design: 2 41 Now let’s check which the confounding pair of factor X4 is. We observe that X4 = - X1X2X3. This means that this is the alternate or complementary fractional design of 2 4III1 We rearrange the treatment combinations and then we proceed to calculate the Effect Estimates, and the Mean Sum Squares x1 -1 1 -1 1 -1 1 -1 1 x2 -1 -1 1 1 -1 -1 1 1 x3 x4 = -x1x2x3 -1 1 -1 -1 -1 -1 -1 1 1 -1 1 1 1 1 1 -1 Factor Level Combination x4 x1 x2 x1x2x4 x3 x1x3x4 x2x3x4 x1x2x3 Coded Response 104 105 107 111 102 105 107 114 1 104 105 107 111 102 105 107 114 15 3.75 4 4 15 2 SS X 1 28.125 8 1 23 X 2 104 105 107 111 102 105 107 114 5.75 4 4 SS X 2 66.125 X1 1 104 105 107 111 102 105 107 114 1 0.25 4 4 0.125 X3 SS X 3 1 104 105 107 111 102 105 107 114 1 0.25 4 4 0.125 X4 SS X 4 1 104 105 107 111 102 105 107 114 7 1.75 4 4 6.125 X 1X 2 SS X 1 X 2 1 104 105 107 111 102 105 107 114 5 1.25 4 4 3.125 X 1X 3 SS X 1 X 3 1 104 105 107 111 102 105 107 114 5 1.25 4 4 3.125 X 2X 3 SS X 2 X 3 Factor Level Combination x1 x2 x3 x4 x1x2 x1x3 x2x3 Effect Estimate 3.75 5.75 0.25 -0.25 1.75 1.25 1.25 SS 28.125 66.13 0.13 0.13 6.13 3.13 3.13 dof 1 1 1 1 1 1 1 MS error = σ MS i F0 28.13 66.13 0.13 0.13 6.13 3.13 3.13 1.4142 19.89 46.76 0.09 0.09 4.33 2.21 2.21 F0.05,1, 7 5.59 5.59 5.59 5.59 5.59 5.59 5.59 Significant Significant The extra runs would definitely have to be involving main effects A, and B and interaction AB 5.16 What design is given in Table E5.16? Perform an appropriate factorial analysis of the data. Would you like to have additional data to clarify what you have seen in this experiment? If four more runs were authorized what would you suggest? Why? If eight more runs were authorized what would you suggest? Why? x1 -1 1 -1 1 -1 1 -1 1 x2 -1 -1 1 1 -1 -1 1 1 x3 1 -1 -1 1 1 -1 -1 1 x4 -1 -1 -1 -1 1 1 1 1 x5 -1 1 1 -1 1 -1 -1 1 y1 18 16 18 15 17 31 18 30 y2 15 18 17 16 19 30 18 27 Solution Since we have 5 factors the total number of treatments for the complete 2 5 factorial design should be thirty two. We observe only eight in the fractional design. This means that this is a one-fourth fraction factorial design: 2 52 Now let’s check which the confounding pair of factor X3 is. We observe that X3 = X1X2. This means that this is the a fractional design of 25III2 We set the treatment combinations and then we proceed to calculate the Effect Estimates, and the Mean Sum Squares x1 -1 1 -1 1 -1 1 -1 1 x2 x3 = x1x2 -1 1 -1 -1 1 -1 1 1 -1 1 -1 -1 1 -1 1 1 x4 x5 = x1x2x4 -1 -1 -1 1 -1 1 -1 -1 1 1 1 -1 1 -1 1 1 y1 18 16 18 15 17 31 18 30 y2 15 18 17 16 19 30 18 27 Factor Level Coded Combination Response x3 33.0 x1x5 34.0 x2x5 35.0 x1x2x3 31.0 x3x4x5 36.0 x1x4 61.0 x2x4 36.0 x1x2x3x4x5 57.0 We determine the interactions that are not confounded with any of the five main effects I x1 x2 x3 x4 x5 x1x2 x1x3 x1x4 x1x5 x2x3 x2x4 x2x5 x3x4 x3x5 x4x5 = x1x2x3 = x2x3 = x1x3 = x1x2 = x1x2x3x4 = x1x2x3x5 = x3 = x2 = x2x3x4 = x2x3x5 = x1 = x1x3x4 = x1x3x5 = x1x2x4 = x1x2x5 = x1x2x3x4x5 = x1x2x4x5 = x2x4x5 = x1x4x5 = x1x2x3x4x5 = x1x2x5 = x1x2x4 = x4x5 = x2x3x4x5 = x2x5 = x2x4 = x1x3x4x5 = x1x5 = x1x4 = x1x2x3x5 = x1x2x3x4 = x1x2 I x1 x2 x3 x4 x5 x1x2 x1x3 x1x4 x1x5 x2x3 x2x4 x2x5 x3x4 x3x5 x4x5 = x1x2x3 = x2x3 = x1x3 = x1x2 = x1x2x3x4 = x1x2x3x5 = x3 = x2 = x2x3x4 = x2x3x5 = x1 = x1x3x4 = x1x3x5 = x1x2x4 = x1x2x5 = x1x2x3x4x5 = x1x2x4x5 = x2x4x5 = x1x4x5 = x1x2x3x4x5 = x1x2x5 = x1x2x4 = x4x5 = x2x3x4x5 = x2x5 = x2x4 = x1x3x4x5 = x1x5 = x1x4 = x1x2x3x5 = x1x2x3x4 = x1x2 X1X4 and X1X5 are not confounded with any of the five main factors. Next we calculate the effect estimator 1 33 34 35 31 18 30.5 18 28.5 43 5.375 8 8 2 43 SS X 1 115.56 16 1 5 X 2 33 34 35 31 36 61 36 57 0.625 8 8 SS X 2 1.5624 X1 1 33 34 35 31 36 61 36 57 9 1.125 8 8 5.0624 X3 SS X 3 1 33 34 35 31 36 61 36 57 57 7.125 8 8 203.0624 X4 SS X 4 1 33 34 35 31 36 61 36 57 1 0.125 8 8 0.0625 X5 SS X 5 1 33 34 35 31 36 61 36 57 49 6.125 8 8 150.04 X 1X 4 SS X 1 X 4 1 33 34 35 31 36 61 36 57 3 0.375 8 8 1.125 X 1X 5 SS X 1 X 5 Factor Level Combination x1 x2 x3 x4 x5 x1x4 x1x5 k 3 n2 N 2 * 8 16 Effect Estimate 2.6875 -0.3125 0.5625 3.5625 0.0625 3.0625 -0.1875 SS dof 115.560 1.562 5.062 203.062 0.063 150.040 1.125 476.475 1 1 1 1 1 1 1 MS i F0 115.56 66.21 1.56 0.90 5.06 2.90 203.06 116.35 0.06 0.04 150.04 85.97 1.13 0.64 F0.05,1, 7 5.59 Significant 5.59 5.59 5.59 Significant 5.59 5.59 Significant 5.59 y i 163 160 323 y i2 7011 ( 323 ) 2 SST 7011 490 . 4375 16 SSE 490 . 4375 476 . 475 13 . 9625 MSE SSE 13 . 9625 1 . 7453 ( n 1) 2 k 8 From this result we are faced with the large significance of X1, X4, and X1X4. So we do a full factorial design with only the two influential factors and their interaction with each other. The more runs allowed the better! Problems from the book pages Chapter 8 8-4 Problem 6-21 describes a process improvement study in the manufacturing process of an integrated circuit. Suppose that only eight runs could be made in this process. Set up an appropriate 2 52 design and find the alias structure. Use the appropriate observations from problem 6-21 as the observations in this design and estimate the factor effects. What conclusions can you draw? RUN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 A -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 B -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 C -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 1 1 1 1 D -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1 1 1 1 1 E Treatment -1 I -1 a -1 b -1 ab -1 c -1 ac -1 bc -1 abc -1 d -1 ad -1 bd -1 abd -1 cd -1 acd -1 bcd -1 abcd YIELD 7 9 34 55 16 20 40 60 8 10 32 50 18 21 44 61 RUN 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 A -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 B -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 C -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 1 1 1 1 D -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1 1 1 1 1 E Treatment 1 e 1 ae 1 be 1 abe 1 ce 1 ace 1 bce 1 abce 1 de 1 ade 1 bde 1 abde 1 cde 1 acde 1 bcde 1 abcde YIELD 8 12 35 52 15 22 45 65 6 10 30 53 15 20 41 63 Design Generators D = AB, and E = AC Here you can see the eight treatment combinations for which the Design Generators are true RUN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 A -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 B -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 C -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 1 1 1 1 D -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1 1 1 1 1 D = AB E E = AC Treatment YIELD RUN A B C D D = AB E E = AC Treatment YIELD 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 1 -1 1 -1 -1 1 -1 1 1 -1 1 -1 -1 1 -1 1 I a b ab c ac bc abc d ad bd abd cd acd bcd abcd 7 9 34 55 16 20 40 60 8 10 32 50 18 21 44 61 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1 1 1 1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -1 1 -1 -1 1 -1 1 1 -1 1 -1 -1 1 -1 1 e ae be abe ce ace bce abce de ade bde abde cde acde bcde abcde 8 12 35 52 15 22 45 65 6 10 30 53 15 20 41 63 RUN 2 7 12 13 19 22 25 32 A 1 -1 1 -1 -1 1 -1 1 B -1 1 1 -1 1 -1 -1 1 C -1 1 -1 1 -1 1 -1 1 Factor Level D = AB E = AC Combination -1 -1 a -1 -1 bc 1 -1 abd 1 -1 cd -1 1 be -1 1 ace 1 1 de 1 1 abcde Coded Response 9 40 50 18 35 22 6 63 Since we don’t have the proper set up for using Yates Algorithm to calculate the Effect Estimators we proceed to use the following formulas: 1 9 40 50 18 35 22 6 63 45 11.25 4 4 1 133 B 9 40 50 18 35 22 6 63 33.25 4 4 1 43 C 9 40 50 18 35 22 6 63 10.75 4 4 1 31 D 9 40 50 18 35 22 6 63 7.75 4 4 1 9 E 9 40 50 18 35 22 6 63 2.25 4 4 1 7 BC 9 40 50 18 35 22 6 63 1.75 4 4 1 7 BE 9 40 50 18 35 22 6 63 1.75 4 4 A 1 45 2 2 SS A 9 40 50 18 35 22 6 63 253.125 8 8 1 1332 2 SS B 9 40 50 18 35 22 6 63 2211.125 8 8 1 432 2 SS C 9 40 50 18 35 22 6 63 231.125 8 8 1 312 2 SS D 9 40 50 18 35 22 6 63 120.125 8 8 1 92 2 SS E 9 40 50 18 35 22 6 63 10.125 8 8 2 1 7 2 SS BC 9 40 50 18 35 22 6 63 6.125 8 8 1 72 2 SS BE 9 40 50 18 35 22 6 63 6.125 8 8 Factor Level Combination A B C D E BC BE Effect Estimate 11.25 33.25 10.75 7.75 2.25 -1.75 1.75 We Graph the Effect Estimators in a Probability Plot and determine that the main effects A, B, C, and D are large, but we keep in mind, however that what we are really estimating is: A + BD + CE B + AD C + DE D + AD So there could be other interpretations because of the aliases Factor Level Combination A B C D Effect SS Estimate 11.25 253.125 33.25 2211.130 10.75 231.125 7.75 120.125 dof MS i 1 1 1 1 253.13 2211.13 231.13 120.13 F0 33.93 47.64 4.98 2.59 8-5 Suppose that you have made the eight runs in the 25-2 design in problem 8-4. What additional runs would be required to identify the factor effects that are of interest? What are the alias relationships in the combined design? A fold over of the original design may be done by changing the sign on the generator. If we assume that all three factors and the higher interactions are insignificant, this would mean that all main effects can be separated from their two-factor interaction aliased in the combined design PROBLEM EXAMPLE Thanksgiving Turkey AGE IN WEEKS WEIGHT (lbs) ORIGIN ei 28 13.31 Georgia -0.4 20 8.9 Georgia -1.4 32 15.1 Georgia -0.2 22 10.4 Georgia -0.8 AGE IN WEEKS WEIGHT (lbs) ORIGIN ei 29 13.1 Virginia -1 27 12.4 Virginia -0.8 28 13.2 Virginia -0.5 26 11.8 Virginia -1 AGE IN WEEKS WEIGHT (lbs) ORIGIN ei Solution Next page 21 27 29 23 25 11.5 14.2 15.4 13.1 13.8 Wisconsin Wisconsin Wisconsin Wisconsin Wisconsin 0.8 1 1.3 1.5 1.4 PROBLEM FROM HANDOUT PAGE 14-30 Since there are 6 factors and only 8 treatment combinations we can say that this is a 2 6III3 . The Generator is: I = ABD = -ACE = BCF The effect estimators are as follows: 1 165 55 35 105 95 105 25 215 160 40 4 4 130 B 32.5 4 80 C 20 4 360 D 90 4 240 E 60 4 120 F 30 4 110 AD 27.5 4 0 CD 0 4 120 DE 30 4 25600 SS A 3200 8 16900 SS B 2112.5 8 6400 SS C 800 8 129600 SS D 16200 8 57600 SS E 7200 8 14400 SS F 30 8 SS AD 1512.5 A SS CD 0 SS DE 1800 Factor Level Effect SS dof MS i Combination Estimate A 40.00 3200.00 1 3200.00 B -32.50 2112.50 1 2112.50 C 20.00 800.00 1 800.00 D 90.00 16200.00 1 16200.00 E -60.00 7200.00 1 7200.00 F 30.00 30.00 1 30.00 AD -27.50 1512.50 1 1512.50 CD 0 0.00 1 0.00 DE -30 1800.00 1 1800.00