REVISED Z01_REND6289_10_IM_MOD1.QXD 5/15/08 10:55 AM Page 269 1 M O D U L E Analytic Hierarchy Process TEACHING SUGGESTIONS Factor evaluations: Teaching Suggestion M1.1: Using Multifactor Decision-Making Techniques. Many decisions students make involve a number of factors. Thus, multifactor decision-making techniques can be useful and practical. This section can be started by having students give examples of decisions that require the analysis of multiple factors. Buying a car or stereo and picking the best job offer are examples. Once students understand the principles of multiplying factor weights times factor evaluations, they will be able to understand the use of AHP. Teaching Suggestion M1.2: Using AHP. Have the students describe situations where AHP would be preferred over the multifactor evaluation process. You may want to take one of these situations and show how pairwise comparisons can be made. Students can then be asked to complete the AHP problem and determine the best solution. This can lead to in-class discussions on the AHP process. SOLUTIONS TO QUESTIONS AND PROBLEMS M1-1. Multifactor decision making is appropriate when a decision involves a number of factors. Deciding to buy a house, for example, can involve the price, location, taxes, utilities, and so forth. M1-2. When using multifactor decision making, each factor receives an importance weight. These weights will sum to 1. Then every alternative and factor combination will receive a factor evaluation. The factor weights are multiplied by the factor evaluations to get a weighted evaluation for each alternative. The alternative with the highest weighted evaluation is selected. M1-3. The analytic hierarchy process should be used when it is difficult or impossible to determine factor weights and factor evaluations subjectively. In this case, pairwise comparisons are performed to assist in the decision-making process and determine the best alternative. M1-4. Here is an analysis of George’s decision. Factor weights: Factor Importance (Weight) Price Color Warranty Size Brand name 0.4 0.1 0.1 0.1 0.3 Factor Sun Hitek Surgo Price Color Warranty Size Brand name 0.7 0.9 0.8 0.8 0.9 0.6 0.9 0.9 0.8 0.9 0.8 0.4 0.4 0.2 0.6 Evaluation of SUN: Factor Name Factor Rating Factor Evaluation Weighted Evaluation Price Color Warranty Size Brand name Total 0.4 0.1 0.1 0.1 0.3 1.0 0.7 0.9 0.8 0.8 0.9 0.28 0.09 0.08 0.08 0.27 0.80 Factor Name Factor Rating Factor Evaluation Weighted Evaluation Price Color Warranty Size Brand name Total 0.4 0.1 0.1 0.1 0.3 1.0 0.6 0.9 0.9 0.8 0.9 0.24 0.09 0.09 0.08 0.27 0.77 Evaluation of HITEK: Evaluation of SURGO: Factor Name Factor Rating Factor Evaluation Weighted Evaluation Price Color Warranty Size Brand name Total 0.4 0.1 0.1 0.1 0.3 1.0 0.8 0.4 0.4 0.2 0.6 0.32 0.04 0.04 0.02 0.18 0.60 SUN is selected, with the highest total weighted evaluation of 0.80. 269 REVISED Z01_REND6289_10_IM_MOD1.QXD 270 5/15/08 MODULE 1 M1-5. 10:55 AM Page 270 ANALYTIC HIERARCHY PROCESS Consistency information follows: Linda’s problem can be analyzed as follows: Price Car 1 Car 1 Car 2 Car 3 Car 2 Car 3 2 7 4 Weighted sum vector ⫽ (0.7096 2.0468 0.2460) Consistency vector ⫽ (3.0011 3.0031 3.0004) Lambda ⫽ 3.0015 Value of CI ⫽ 0.0008 RI ⫽ 0.5800 The following will be the priorities for price: CR ⫽ 0.0013 Priority for car 1 is 0.6025. Priority for car 2 is 0.3151. Priority for car 3 is 0.0824. M1-8. Factors Consistency information follows: Price Price Warranty Style Weighted sum vector ⫽ (1.8096 0.9460 0.2473) Consistency vector ⫽ (3.0035 3.0019 3.0005) Warranty Style 2 9 6 Lambda ⫽ 3.0020 The following will be the priorities for the factors: Value of CI ⫽ 0.0010 Priority for price is 0.6049. Priority for warranty is 0.3337. Priority for style is 0.0614. RI ⫽ 0.5800 CR ⫽ 0.0017 M1-6. Consistency information follows: Warranty Car 1 Car 1 Car 2 Car 3 1 3 1 8 Weighted sum vector ⫽ (1.8246 1.0044 0.1842) Consistency vector ⫽ (3.0163 3.0097 3.0016) Value of CI ⫽ 0.0046 1 5 Car 2 RI ⫽ 0.5800 Car 3 CR ⫽ 0.0079 The following are the final rankings—Car 1 is selected. The following will be the priorities for warranty: Priority for car 1 is 0.0768. Priority for car 2 is 0.1863. Priority for car 3 is 0.7370. Consistency information follows: Weighted sum vector ⫽ (0.2310 0.5640 2.2825) Consistency vector ⫽ (3.0088 3.0276 3.0972) Lambda ⫽ 3.0445 RI ⫽ 0.5800 CR ⫽ 0.0384 M1-7. Car 1 Car 1 Car 2 Car 2 Car 3 1 3 3 8 Car 3 The following will be the priorities for style: Priority for car 1 is 0.2364. Priority for car 2 is 0.6816. Priority for car 3 is 0.0820. Ranking 0.4045 0.2946 0.3008 M1-9. The weighted averages of these scores are shown in the table. Gina should choose Univesity B. Value of CI ⫽ 0.0223 Style Item Car 1 Car 2 Car 3 Weight Cost 0.6 Reputation 0.2 A B C 4 8 7 9 5 6 M1-10. Quality of life 0.2 Weighted Average 7 7 3 5.6 7.2 6.0 Using AHP, we have the following matrices. Cost A B C Column Total A 1 5 3 9 Normalized A B C Factor Evaluation (Row Average) 0.1111 0.5556 0.3333 0.1304 0.6522 0.2174 0.0769 0.6923 0.2308 0.1062 0.6333 0.2605 A B C B C 0.2 0.333333 1 3 0.333333 1 1.533333 4.333333 REVISED Z01_REND6289_10_IM_MOD1.QXD 5/15/08 10:55 AM Page 271 MODULE 1 Reputation A A 1 B 0.142857 C 0.2 Column Total 1.342857 Normalized A B C A 0.7447 0.1064 0.1489 B 7 1 3 11 C 0.7895 0.0526 0.1579 271 The following will be the priorities for price: C 5 0.333333 1 6.333333 B 0.6364 0.0909 0.2727 ANALYTICAL HIERARCHY PROCESS Priority for system 1 (S-1) is 0.6039. Priority for system 2 (S-2) is 0.3258. Priority for system 3 (S-3) is 0.0703. Consistency information follows: Factor Evaluation (Row Average) 0.7235 0.0833 0.1932 Weighted sum vector ⫽ (1.8178 0.9792 0.2109) Consistency vector ⫽ (3.0099 3.0056 3.0011) Lambda ⫽ 3.0055 Value of CI ⫽ 0.0028 RI ⫽ 0.5800 CR ⫽ 0.0048 Quality of Life A B C Column Total Normalized A B C A 1 1 0.2 2.2 B 1 1 0.142857 2.142857 C 5 7 1 13 A B C 0.4545 0.4545 0.0909 0.4667 0.4667 0.0667 0.3846 0.5385 0.0769 Brand Name S-1 S-1 S-2 S-3 Factor Evaluation (Row Average) 0.4353 0.4866 0.0782 S-2 S-3 1 6 4 The following will be the priorities for brand name: Priority for system 1 (S-1) is 0.4838. Priority for system 2 (S-2) is 0.4232. Priority for system 3 (S-3) is 0.0930. Consistency information follows: Weighted sum vector ⫽ (1.4649 1.2789 0.2794) Factors Cost Reputation Quality of life Column Total Cost 1 0.333333 0.142857 1.47619 Reputation 3 1 0.5 4.5 Consistency vector ⫽ (3.0278 3.0220 3.0051) Quality of life 7 2 1 10 Lambda ⫽ 3.0183 Value of CI ⫽ 0.0092 RI ⫽ 0.5800 CR ⫽ 0.0158 Normalized Cost Reputation Quality of life Quality Cost Reputation of life 0.6774 0.6667 0.7000 0.2258 0.2222 0.2000 0.0968 0.1111 0.1000 Factor Evaluation (Row Average) 0.6814 0.2160 0.1026 Using the factor weights, we find the following weighted averages for each university. Memory S-1 S-1 S-2 S-3 1 2 1 7 1 6 S-2 S-3 The following will be the priorities for memory: A B C Weights Cost Reputation Quality of life 0.1062 0.7235 0.4353 0.6333 0.0833 0.4866 0.2605 0.1932 0.0782 0.6814 0.2160 0.1026 Weighted Average 0.2733 0.4995 0.2272 Priority for system 1 (S-1) is 0.0919. Priority for system 2 (S-2) is 0.1535. Priority for system 3 (S-3) is 0.7545. Consistency information follows: Weighted sum vector ⫽ (0.2765 0.4631 2.3192) Consistency vector ⫽ (3.0078 3.0164 3.0736) Therefore, Gina should choose University B. Lambda ⫽ 3.0326 Value of CI ⫽ 0.0163 RI ⫽ 0.5800 M1-11. The analysis to determine which computer system is to be selected is as follows: Price S-1 S-2 S-3 S-1 S-2 2 S-3 8 5 CR ⫽ 0.0281 Speed S-1 S-2 S-3 S-1 S-2 S-3 1 3 2 5 REVISED Z01_REND6289_10_IM_MOD1.QXD 272 5/15/08 MODULE 1 10:55 AM Page 272 ANALYTIC HIERARCHY PROCESS Table for Factors for Problem M1-11 Factors Price Brand Name Memory Speed Flexibility PC Compatibility 9 4 5 1 3 2 1 4 1 5 2 1 2 1 6 1 3 1 6 Price Brand name 1 2 Memory Speed 1 2 Flexibility PC compatible Consistency information follows: The following will be the priorities for speed: Weighted sum vector ⫽ (2.1717 0.2371 0.6218) Priority for system 1 (S-1) is 0.2299. Priority for system 2 (S-2) is 0.6479. Priority for system 3 (S-3) is 0.1222. Consistency vector ⫽ (3.0389 3.0040 3.0122) Lambda ⫽ 3.0184 Consistency information: Value of CI ⫽ 0.0092 Weighted sum vector ⫽ (0.6902 1.9485 0.3667) RI ⫽ 0.5800 Consistency vector ⫽ (3.0026 3.0071 3.0013) CR ⫽ 0.0158 Lambda ⫽ 3.0037 The following will be the weights for the factors: Value of CI ⫽ 0.0018 RI ⫽ 0.5800 CR ⫽ 0.0032 Flexibility S-1 S-1 S-2 S-3 1 2 1 8 1 4 S-2 Weight for price is Weight for brand name is Weight for memory is Weight for speed is Weight for flexibility is Weight for PC compatibility is 0.3849 0.0447 0.0816 0.0514 0.149 0.288 See the table for factors for Problem M1-11. Consistency information follows: 冢 S-3 Weighted sum vector ⫽ 2.39 0.275 0.312 0.918 The following will be the priorities for flexibility: Priority for system 1 (S-1) is 0.0909. Priority for system 2 (S-2) is 0.1818. Priority for system 3 (S-3) is 0.7273. Consistency vector = 6.2208 冢6.0592 CR ⫽ 0.0232 Consistency vector ⫽ (3.0000 3.0000 3.0000) The following are the final rankings—system 1 (S-1) is selected. Lambda ⫽ 3.0000 Value of CI ⫽ 0.0000 RI ⫽ 0.5800 Item Ranking CR ⫽ 0.0000 System 1 (S-1) System 2 (S-2) System 3 (S-3) 0.4928 0.2400 0.2671 S-1 S-2 S-3 8 S-2 S-3 The following will be the priorities for PC compatibility: Priority for system 1 (S-1) is 0.7146. Priority for system 2 (S-2) is 0.0789. Priority for system 3 (S-3) is 0.2064. 冣 6.1480 6.0362 6.1485 6.2518 RI ⫽ 1.2400 Weighted sum vector ⫽ (0.2727 0.5455 2.1818) S-1 冣 Value of CI ⫽ 0.0288 Consistency information follows: PC Compatibility 0.493 1.801 4 1 3