1. Design Tools 1 William Oakes

2. Learning Objectives • At the end of this session, you will be able to: • Describe a decision matrix • Categorize potential failures for a design • Perform a functional decomposition

3. EPICS Balance • Service-learning is a balance of the learning of design and the service we contribute the communities through completed designs and support • Service • To our partners, meeting needs in the community • Learning • Becoming good designers, professionals & active citizens Complimentary goals that enhance each other

4. Design Tool: Engineering specifications

5. Specifications Development • What does your project partner need? • Don’t just rely on what they want, find out what they need • Understand the problems and issues you are addressing • Who will use product and who will benefit from it? • Gather Data • Talk to Project Partner and others impacted by the project • How will the problem be worked? • Criteria for design teams • How will teams be integrated • Transition plans for multiple semesters • Gather input from project partner on specifications • Develop a specifications document and share it

6. Customer Requirements • Types of customer requirements • Functional performance • Human factors • Physical • Time (reliability) • Cost • Standards • Test Method • Service & maintenance

7. Customer Requirements For a cell phone, make a list of Ten customer requirements

8. Engineering Specifications • Answers the “how” question • Quantified • Should be able to measure whether you meet it • Objective quantities • A set of units should be associated with each specification • Forms the basis for your specifications document

9. Engineering Requirements Starting with the customer requirements for a cell phone, make a list of engineering requirements

10. Defining Requirements • Benchmarks • What is available • Why did they use their approach • Patent searches • avoid infringement • Protect IP • Are we smarter than everyone else? • Or did we miss something?

11. Design Targets • Set standards to meet with your design • How good is good • Can be a living document • Don’t compromise on goals, but refine as the design progresses • Tool make design trade offs • Design decisions • Communication with project partner

12. Design Tool: Defining the System

13. The EPICS Design Cycle Problem Identification Specification Development Redesign Retirement Conceptual Design Disposal Detailed Design Service Maintenance Production

14. Functional Decomposition • Breaking tasks or functions of the system down to the finest level • Create a tree diagram starting at the most general function of your system • What is the purpose of your system? • Break this function down into simpler subtasks or subfunctions • Continue until you are at the most basic functions or tasks

15. Functional Decomposition Diagram

16. Sample Diagram – Bike Fender

17. Functional Decomposition • Each function has a box with • An action verb • The object(s) on which the verb acts • Possibly a modifier giving details of the function • Known flows of materials, energy, control or information • Consider WHAT not HOW

18. Create a functional decomposition diagram for a mechanical pencil Prepare them to share

19. Generating Ideas - Brainstorming • Pick A Facilitator • Define The Problem • Small Group • Explain the Process • Record Ideas in a Visible Way • Everyone’s Involved • No Evaluating • Eliminate Duplicates • Pick Three

20. In the same groupBrainstorm ways to implement one of the functions on your diagram and select the best alternative Prepare it to share

21. Decision Matrix • Table with alternatives • Quantify categories and score alternatives • Importance in different categories • Use judgement to do reality checks • Leaves documentation of thought process of design • Can be shared in design reviews

22. Ideas to be compared Criteria for Comparison Weights Scores Totals Decision Matrix

23. Decision MatrixExample: Getting a Job

24. DFMEA :Design for Robustness

25. Disposal Problem Identification Specification Development Redesign Retirement Conceptual Design Detailed Design Service Maintenance Production Design Phase: Testing for Failures • Planning to avoid failures

26. DFMEA Steps • Review the design • Brainstorm potential failure modes • List potential effects of failure • Rank failures • Severity • Occurrence • Detection • Develop action plan • Implement fixes • Revisit potential failure risks

27. In a group, Identify one project to use as an example for this exercise Describe the project so the whole group understands it

28. Brainstorm Failures • What could go wrong? • What could break? • Are there systems your design relies upon? • e.g. myEPICS authenticates through Purdue’s career accounts • Are there things that could fail over time?

29. Brainstorm a list of potential failures for the project

30. Rate failures

31. DFMEA Matrix

32. Identify the failure scenario that should be addressed first

33. Develop an action plan to address the failure scenario

34. Continue the process • Implement the plan to eliminate the failure scenario • Revisit other potential failure risks • Prioritize • Eliminate failure scenarios • Continue until risks are below determined thresholds • Show to the design reviews for confirmation

35. Questions/Discussion