ECET 4550: Alternate Energy fall 2011

1. ECET 4550:Alternate Energyfall 2011 Laboratory Topic: The Design Process Florian Misoc, 2010

2. Announcement • Third week in October (15-21): FE examination practice • Contact Dr. John Krohn, Mechanical Engineering Department • Suggestion: every graduating engineering student should take the FE exam (Fundamentals of Engineering) Florian Misoc, 2010

3. Chapter Objectives • Description and Prescription • Strategies, Methods & Means • Managing the Design Process • Case Study & Examples Florian Misoc, 2010

4. Introduction • Design Process ≠ “cooking” recipe • Design Process =Σ design tasks = task-1 + task-2 + …. + task-n • Design Process = “framework” • Design process = process of questioning “knowledge resides in the questions that can be asked and the answers that can be provided” Aristotle Florian Misoc, 2010

5. Introduction • Task # 1: Clarify what the client wants • Task # 2: Translate “want” into meaningful objectives • Task # 3: Determine the constrains (limitations) associated with client’s “want” • Task # 4: Establish the “function” of the future system (what does it do?) Florian Misoc, 2010

6. Introduction • Task # 5: Establish set of requirements (specs) • Task # 6: Generate design alternatives • Task # 7: Model and analyze designs • Task # 8: Test and evaluate design alternatives • Task # 9: Refine and optimize the design • Task # 10: Document the design process • Task # 11: Communicate the completed design Florian Misoc, 2010

7. Questions • Task # 1: Clarify what the client wants: • Why do you want another system, device, etc.? • How it will have to work? • How much can it cost? • Task # 2: Translate “want”; • What does “safe” means? • What would the system would be used for? Florian Misoc, 2010

8. Questions • Task # 3: Determine the constrains: • What are the conditions of operations? • What is the system impact on people’s safety? • Task # 4: Establish the “function”: • What is the weight, volume, mass distribution, etc. that the system should accommodate? • Would the system operate indoors /outdoors? Florian Misoc, 2010

9. Questions • Task # 5: Establish set of requirements (specs) • How much weight, voltage, current, should the system withstand? • What is the expected “breaking point”? • Task # 6: Generate design alternatives • Could the system be modular? • What are the alternative materials to be used? Florian Misoc, 2010

10. Questions • Task # 7: Model and analyze designs • What are the maximum stresses (weight, current, etc.) on the system? • How do stresses affect the material(s) • Task # 8: Test and evaluate design alternatives • Does the system meet OSHA requirements? • Can the system accommodate a wide spectrum of users? Florian Misoc, 2010

11. Questions • Task # 9: Refine and optimize the design • Are there other methods of assembly? • Can the amount of material/components used, be reduced? • Task # 10: Document the design process • What are the justifications for choosing “this design”? • What information is needed for manufacture? Florian Misoc, 2010

12. Design Process: Description and Prescription • Describing the Design Process • Prescribing the design Process • Feedback from the Client • Iteration(s) in the design Process • Opportunities and Limits Florian Misoc, 2010

13. Describing the Design Process • Three-phase design process: • Generation: designer generates various design concepts • Evaluation: designer tests the chosen design against objectives and requirements • Communication:designer communicates the final design to the client and to the manufacturer Florian Misoc, 2010

14. Describing the Design Process • Alternate three-phase design process: • Research: designer reviews the existing literature on the subject • Creating: designer generates design prototype • Implementing:designer implements & tests design prototype Florian Misoc, 2010

15. Describing the Design Process • Three stage linear model for design process Florian Misoc, 2010

16. Describing the Design Process • Five stage linear model for design process Florian Misoc, 2010

17. Describing the Design Process • Problem Definition: • Pre-process stage • Frames the problem • Clarifies the client’s original problem statement • Design Communication: • Post-process stage • Identifies the work done • Presents final design & manufacture specs Florian Misoc, 2010

18. Prescribing the design Process • Five-phase prescriptive model: Client’s Problem Statement • Problem Definition • Conceptual Design • Preliminary Design • Detailed Design • Design Communication Documentation for Final Design Florian Misoc, 2010

19. 1. Problem Definition • Clarify objectives • Establish metrics for objectives • Identify constrains • Revise client’s Problem Statement Florian Misoc, 2010

20. 2. Conceptual Design • Establish functions • Establish requirements (specifications) • Establish means for functions • Generate design alternatives • Refine & apply metrics to design alternatives • Choose a design Florian Misoc, 2010

21. 3. Preliminary Design • Model design • Analyze design performance • Test chosen design • Evaluate chosen design: compare design performances with specifications Florian Misoc, 2010

22. 4. Detailed Design • Refine & optimize chosen design: improve design performances • Assign & fix design details Florian Misoc, 2010

23. 5. Design Communication • Document final design • Present chosen design performances to the client • Emphasize design performance (vis-à-vis specs) • Present possible improvements (as a future option) Florian Misoc, 2010

24. Feedback from the Client • Design process: nonlinear, not sequential • Required elements: • Feedback • Iteration Note Primary focus: Conceptual Design Florian Misoc, 2010

25. a. Feedback • Two (2) types: • Internal feedback loops: tests & evaluation results used to validate/verify design performances. Occurs during the design process • External feedback loops: results provided by the user(s) are used to validate the design. Occurs after the design reaches the market Florian Misoc, 2010

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27. b. Iterations • Definition: repeatedly applying a common method/technique at different points during the design/analysis • It occurs at different levels of abstraction (different degrees of detail) • More detail → less abstract • Don’t loose focus on the original objectives! Florian Misoc, 2010

28. Opportunities and Limits • Focus: Conceptual design • Detailing: Broad themes, logical approaches • Conceptual Design Tools: Not mathematical algorithms • Problem Solving: Not necessarily “rigorous” Florian Misoc, 2010

29. Design Process: Strategies, Methods & Means • Prescriptive design: No information on How to generate the design • Formal Design Methods: • Build “Objective Trees” • Rank “Design Objectives’ • Establish “Metrics” • Perform “Functional Analysis” • Elaborate “Requirements/Specifications” Florian Misoc, 2010

30. Means for acquiring information • Literature review • User survey & questionnaires • Focus groups • Informal interviews • Structured interviews • “Brainstorming” • Benchmarking • Reverse engineering Florian Misoc, 2010

31. Means for analyzing information • Develop metrics • Undertake/design experiments • Conduct proof-of-concept testing • Implement prototype development • Conduct computer simulations • Conduct computer numerical analysis Florian Misoc, 2010

32. Means for testing outcomes & feedback • Scheduled meetings (designer-client-user) • Formal design review (present design to: client, selected users, stakeholders), involves trade-off • Public hearings (expose the design for public review), increasingly the norm • Focus groups (user input on problem definition), asses user reaction to design • Beta testing = almost-but-not-quite-finished version of the product Florian Misoc, 2010

33. Managing the Design Process • Four-phase process: • Project definition: develop an initial understanding of the problem to be solved • Project framing: develop & apply a design plan • Project scheduling: organize the design plan/prioritize • Project tracking / evaluation / control: keep track of TIME, work, cost, etc. Florian Misoc, 2010

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35. Managing the Design Process • Design: a social activity • Design: done by teams (seldom by individuals) • Requires: people with different talents, skills, areas of expertise • Transition from group to functioning team: • Forming • Storming • Norming • Performing • Adjourning Florian Misoc, 2010

36. Project Statements-1 Design of a container to deliver a children’s beverage Designers: Dym, Little, Orwin and Spjut LLC Clients: American Beverage Company (ABC) Users: Children living in the United States Problem Statement: Design a bottle for a new children’s juice product Florian Misoc, 2010

37. Project Statements-2 Design a cooling air-flow system for spinal-fusion hydrostatic vest Designers: Team of students at ATU Client: Memphis Trauma Center Users: Victims of accidents that sustained sever spinal fractures Project Statement: Design an air-flow cooling system that will accommodate the existing spinal-fusion vests for patients who sustained severe spinal fractures Florian Misoc, 2010

38. References • Engineering Design, A Project-Based Introduction, third edition • Authors: Clive L. Dym, Patricl Little, Elizabeth J. Orwin, Erik R. Spjut • ISBN: 978-0-470-22596-7 • Pages: 18 - 45 Florian Misoc, 2010

39. Assignment • Due date: September 15th, 2010 • Exercises 2.1 – 2.4, page 45 • Case study 2.5.1: Design of a microlaryngeal surgical stabilizer • Selected Project & team members for the project Florian Misoc, 2010