ECET 4550: A lternate Energy Fall 2011

1. ECET 4550: Alternate EnergyFall 2011 Laboratory Topic: The Problem to be Solved “Statement of the Problem” Florian Misoc, 2010

2. Chapter Objectives • Identifying and Representing the Client’s Objectives • Measurable Quantities • Setting Priorities • Constrains: Limitations and Delimitations • Case Study and Examples Florian Misoc, 2010

3. Introduction • Problem Definition = the most important step in the design process • Problem Definition: pre-design phase of design • Frame the problem => engineering terms • Focus on tasks 1 – 4: • Clarify Objectives • Establish Metrics for Objectives • Identify Constrains • Revise Client’s Problem Statement Florian Misoc, 2010

4. Identifying and Representing the Client’s Objectives • Client’s original problem statement: • Initial statements: brief, general idea • No hint on: intended market, shape of the product, material to be used, etc. • Initial statement has limitations: errors, bias, imply solutions • Clarify what client wants: what potential users need, • Technological & marketing context Florian Misoc, 2010

5. Identifying and Representing the Client’s Objectives • Errors: incorrect information, faulty and/or incomplete data, mistakes regarding the problem • Biases: presumptions about the situation, involving a person’s preference • Implied Solution: client’s best guess at solutions, frequently found in the original problem statement (related to bias) Florian Misoc, 2010

6. Errors of the Design Process Source: http://softwareindustrialization/CategoryView,category,Design.aspx

7. Errors of the Design Process Source: http://softwareindustrialization/CategoryView,category,Design.aspx

8. Errors of the Design Process Source: http://softwareindustrialization/CategoryView,category,Design.aspx

9. Errors of the Design Process Source: http://softwareindustrialization/CategoryView,category,Design.aspx

10. Identifying and Representing the Client’s Objectives: Questions & Brainstorming Two kinds of activity: • Asking questions of the client/stakeholder, with varying degree of interest in the problem/design • Brainstorming: group effort to generate, retain, and organize new ideas to solve the problem Florian Misoc, 2010

11. Identifying and Representing the Client’s Objectives: Asking Questions Questions to understand the scope of the project: • What features/attributes you desire for …..? • What do you want this …. to do? • Are there already …. with similar attributes? Ask also: • What does it mean? • How are you going to do that? • Why do you want that? Florian Misoc, 2010

12. Identifying and Representing the Client’s Objectives: Brainstorming • Focus on quantity: maxim quantity = quality. Great number of ideas = greater the chance of effective solution. • Withhold criticism: focus on extending or adding to ideas, reserve criticism for a later 'critical stage' of the process • Welcome unusual ideas: looking from new perspectives and suspending assumptions (may provide better solutions) • Combine and improve ideas: Good ideas = combinations of ideas: slogan "1+1=3” Florian Misoc, 2010

13. Brainstorming: preliminary / start-up Florian Misoc, 2010

14. Florian Misoc, 2010

15. Identifying and Representing the Client’s Objectives: Concept Definitions • Objective: something toward which effort is directed (an aim/end-of-action) • Constraint: restricted, compelled to avoid, compelled to perform • Function: fitness for use, “for which a thing is made-for” • Means: method used to attain and end Florian Misoc, 2010

16. Client’s Objectives: Objective Tree Florian Misoc, 2010

17. Measurable Quantities Six Scale Types: • Nominal Scales: distinguish among categories • Partially Ordered Scales: hierarchies • Ordinal Scales: rank / order • Ratio Scales: percentage • Interval Scales: reference to a base-point • Multidimensional Scale: compounds of other scales Florian Misoc, 2010

18. Pair-wise Comparison Chart (PCC) Should be applied in constrained “top-down” fashion: • Objectives are compared when at the same level (in the objective tree) • Higher level objectives: compared first • Only “top objectives” need to be ranked • “Low level objectives” are ranked ONLY for complex systems Florian Misoc, 2010

19. Weighted Objectives: American Beverage Company Florian Misoc, 2010

20. Weighted Objectives: National Beverage Company Florian Misoc, 2010

21. Pair-wise Comparison Chart (PCC) • Pair-wise comparison chart for the “ladder design” Florian Misoc, 2010

22. Measuring Achievement of Objectives • VDI 2225: VerbandDeutscherIngenieure/ Association of German Engineers • No Mathematical foundation for scaling or normalizing the PCC ranking • PCC ranking = subjective preferences • Never weigh objectives: it could amplify the error (no mathematical foundation) Florian Misoc, 2010

23. Scale of Awarding Points Florian Misoc, 2010

24. Metrics for Objectives • Metric = repeatable: conducting the test/experiment (under identical conditions & restrains) would lead to identical results/outcomes • Metric outcomes: understandable units of measure • Metric assessment: unambiguous interpretation Florian Misoc, 2010

25. Setting Priorities “Lack of planning from your part does not translate in a priority from my part…” Priority level: determined in the same fashion as awarding points Priority # 1: SAFETY!!! (read the “oath of the engineer”) Florian Misoc, 2010

26. Constrains: Limitations and Delimitations • Limitations:are imposed by the available equipment, environmental conditions, time constrains, etc., and are out of experimenter’s control • Delimitations: are imposed by the experimenter, as to restrict the purpose of said research Florian Misoc, 2010

27. Case Study and Examples Read and summarize: • Example 3.4.2: Establishing metrics for the beverage container • Example 3.6.1: Objectives and Constrains for the “Danbury Arm Support” • Example 3.6.2: Metrics for the Objectives “Danbury Arm Support” Due: same time as assignment of Chapter 3 Florian Misoc, 2010

28. Assignment: • Exercise # 3.1, page 77 • Exercise # 3.2, page 77 & 78 • Exercise # 3.5, page 78 • Exercise 3.6, page 78: as it applies to your particular group project Florian Misoc, 2010