1. 1 As Class Convenes u Find your team u Sign attendance form u Insert any work due today and u Return folder to the front desk

2. 2 As Class Convenes u Find your team, sign attendance form, insert any work due today, and return folder to the front desk u Bring up today’s presentation

3. 3 Session Agenda u Getting Started5 min u Using Relative15 min Ranking in Scoring Tables u Using Absolute30 min Ratings in Scoring Tables

4. 4 Learning Objective Achieve awareness of the differences between Relative Ratings and Absolute Ratings in completing Scoring Tables (Matrices)

5. 5 Session Agenda u Getting Started5 min u Using Relative15 min Rating in Scoring Tables u Using Absolute30 min Ratings in Scoring Tables

6. 6 Sample Scoring Table

7. 7 Concept Scoring Tables u Scoring Tables are similar to what? a prioritization matrix u What does a Scoring Table do? it rates and ranks Concepts relative to a set of Selection Criteria

8. 8 Determining Ratings: The Text Book Says u Use relative comparisons u Use a simple rating scale 1 = much worse than reference to 5 = much better than reference

9. 9 Problems With Relative Rating u Scale Compression –if reference concept is the best relative to criterion 1, what rating values are available for criterion 1? –only 1 (much worse), 2 (worse) & maybe 3 (same) u Not rigorous for non experts

10. 10 In Some Cases We Can Do Better u Use absolute instead of relative rating of concepts u Use engineering science to predict the values of the criteria for the concepts

11. 11 A Class Exercise For a two criteria, three “concepts” problem, you will evaluate the “concepts” 1using relative rating 2using absolute values with mapping to a rating

12. 12 The Problem NASA wants to launch another probe to Mars. This probe requires a widget that TeamUSA has agreed to design and make. NASA wants a low mass, low cost widget. Three feasible concepts have been created; which one should be selected?

13. 13 Three Widget Concepts A an ABS plastic cube 4.8 cm on a side, $2000 B a Bakelite rod 5.0 cm long & 2.5 cm in diameter, $4000 C a glass rod 5.0 cm long & 2.8 cm in diameter, $6000

14. 14 Relative Rating Scale  Much Worse  Worse  About the Same  Better  Much Better light is better than heavy

15. 15 Rate Concepts Using Relative Comparison Method Using Concept C as the reference, rate Concepts A & B 3 41

16. 16 Session Agenda u Getting Started5 min u Using Relative15 min Ranking in Scoring Tables u Using Absolute30 min Ratings in Scoring Tables

17. 17 Using Absolute Ratings u Evaluate the criterion for each concept, i.e., calculate the mass of each concept

18. 18 Effect of Mapping on Selection

19. 19 Using Absolute Ratings  Why can't you use the calculated mass directly in the Scoring Table?  You can change the results in the table by just changing the units (metric tons vs micro grams)

20. 20 Using Absolute Ratings (cont’d) u You need to map the calculated masses into a dimensionless 1 to 5 rating scale u What is a map? A map is a function that converts one value (e.g., a criterion value) into another value (e.g., a rating)

21. 21

22. 22

23. 23

24. 24 Rate The Concepts Using Absolute Comparison Method Using your team’s map, rank Concepts A, B, & C 1123780

25. 25 Summary of Mapping Results 2 1.1 4.8 2 4.53 1.6 4.24

26. 26 Analysis of Scoring Tables u Does the mapping change the relative rankings? no, A is always the worst and B is always the best u What does change with different mappings? the value in the table, A ranges from 1 to 4

27. 27 Effect of Mapping on Selection

28. 28 Effect of Mapping on Selection

29. 29 Effect of Mapping on Selection

30. 30 Effect of Mapping on Selection

31. 31 Effect of Mapping on Selection

32. 32 Effect of Mapping on Selection

33. 33 Effect of Mapping on Selection