OVERVIEW

1. OVERVIEW • Debate in engineering design community: Should design be taught as: • Establishing a foundation of theory? or • Engaging students in loosely supervised practice? • Reject both approaches when taken to extremes • Theory without practice is ineffective because there are many nuances, exceptions, and subtleties to be learned in practical settings • Practice without guidance can be very frustrating and often fails to exploit knowledge and expertise • Focus on methodology • Step-by-step procedure for completing a task • Does not embody a clean and concise theory MAE 4291: Senior Design 1

2. PRODUCT DEVELOPMENT PROCESS MAE 4291: Senior Design 1

3. GENERIC DEVELOPMENT PROCESS • Concept Development • Identifying customer needs • Establishing target specifications • Analysis of competitive products • Concept generation • Concept selection • Refinement of specifications • Economic analysis • Project planning • A concept is a description of the form, function, and features or a product and is usually accompanied by a set of specifications, an analysis of competitive products, and an economic justification for the project MAE 4291: Senior Design 1

4. GENERIC DEVELOPMENT PROCESS • System Level Design • Definition of the product architecture and the division of the product into subsystems and components • Output: • Geometrical layout of the product • Functional specification of each of the products subsystems • Preliminary process flow diagram for assembly MAE 4291: Senior Design 1

5. GENERIC DEVELOPMENT PROCESS • Detailed Design • Complete specification of geometry, materials, and tolerances for all parts • Identification of all of the standard parts to be purchased from suppliers • Output • Control documentation: drawings (or computer files) describing all details of the geometry of each part and tooling specifications MAE 4291: Senior Design 1

6. GENERIC DEVELOPMENT PROCESS • Testing and Refinement • Construction and evaluation of multiple versions (prototypes) of the product • Alpha prototype: determine whether or not the product will work as designed and whether or not product meets customer needs • Beta prototype: extensively evaluated internally and examine performance and reliability to identify changes prior to final design MAE 4291: Senior Design 1

7. MAE HISTORICAL OBSERVATIONS • Many (perhaps even most) MAE senior design teams get stuck in (1) and (2) and not enough effort is placed in (3) and (4) • Good connection between (1) and (2) • Significant disconnect between how (3) and (4) fit into (1) and (2) • Significant disconnect between how (3) and (4) go together MAE 4291: Senior Design 1

8. MAE 4291: Senior Design 1

9. EXAMPLE OF PROJECT PLAN MAE 4291: Senior Design 1

10. ESTABLISHING SPECIFICATIONS

11. EXAMPLE: MOUNTAIN BIKE FRONT SUSPENSION • Example of customer specified needs • Includes importance relative importance • 5 most important, 1 least important • Note how vague statements are, and how much margin for subjective interpretation • Example: “Suspension is easy to install” versus “the average time to assemble the fork to the frame is less than 75 seconds” MAE 4291: Senior Design 1

12. EXAMPLE: MOUNTAIN BIKE FRONT SUSPENSION MAE 4291: Senior Design 1

13. NEEDS – METRICS MATRIX • Shows relationship between needs and metrics and assures that all of customer needs are considered • Often called ‘House of Quality’ – graphical technique • Metrics are dependent varaibles • Metrics should be practical MAE 4291: Senior Design 1

14. COMPETITIVE BENCHMARKING • Very important for commercial products in a competitive market place (unless you have a monopoly) • Compare other products with the metrics that you have determined • Use this information to rank other products MAE 4291: Senior Design 1

15. TARGET SPECIFICATIONS • Now have a quantitative measure of how to meet customer needs • Will facilitate development of technical and cost models • Will inherently be refined as design process continues MAE 4291: Senior Design 1

16. EXAMPLE OF TECHNICAL MODELS • What design variables do you have that can control the metrics? • Foundation for the development of a ‘serious’ math model MAE 4291: Senior Design 1

17. CONCEPT GENERATION

18. EXAMPLE: NAILGUN • Understanding the problem • External searches • Literature review • Talking to companies • Internal searches • Individual and group ideas • Systematically assess each concept MAE 4291: Senior Design 1

19. EXAMPLES OF CLASSIFICATION • Classification tree for nailer energy sources • Problem deomposition assuming an electrical energy source and accumulation of energy in mechanical domain and concept combination table MAE 4291: Senior Design 1

20. POTENTIAL CONCEPTS Concept 2 Concept 1 Concept 3 • Concept 1: solenoid compresses a spring and then releases it repeatedly in order to drive the nail with multiple impacts • Concept 2: multiple solutions arising from combination for a motor with transmission – motor winds a spring, accumulating potential energy which is delivered to the nail in a single blow • Concept 3: combination of motor with transmission – motor repeatedly winds and releases the spring, driving the nail with multiple blows. MAE 4291: Senior Design 1

21. CONCEPT RANKING AND SELECTION • Example of concept screening matrix • Develop your own ranking methodology • The process is what is important MAE 4291: Senior Design 1