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Engineering Design Curriculum. Courtesy of: www. engineering -ed.org/documents/week_1_ design _process. ppt. Course Objectives. Apply the engineering design process Define a problem (need) and develop alternatives for solving Build, test, evaluate prototypes
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Engineering Design Curriculum Courtesy of: www.engineering-ed.org/documents/week_1_design_process.ppt
Course Objectives • Apply the engineering design process • Define a problem (need) and develop alternatives for solving • Build, test, evaluate prototypes • Create and use engineering drawings • Demonstrate drafting techniques
Engineering design is… • the process of devising a system, component or process to meet needs • a decision-making process in which science and mathematics are applied to convert resources to meet objectives • establishing objectives & criteria, synthesis, analysis, construction, testing, and evaluation
Engineering Problem Problem statement incomplete, ambiguous No readily identifiable closure Solutions neither unique nor compact Solution needs integration of many specialties Science Problem Succinct problem statement Identifiable closure Unique solution Problem defined and solved with specialized knowledge Problem Characteristics
Typical Design Problems “Design a system for lifting and moving loads of up to 5000 lb in a manufacturing facility. The facility has an unobstructed span of 50 ft. The lifting system should be inexpensive and satisfy all relevant safety standards.”
Studying Engineering Design • Develop student creativity • Use open-ended problems • Use design theory and methods • Formulate design problem statements and specifications • Consider alternative solutions • Consider feasibility
Studying Engineering Design • Know and apply production processes • Understand concurrent engineering design • Create detailed system descriptions • Include realistic constraints such as… • Economic factors, safety, reliability • aesthetics, ethics, social impacts
“Awesome” Engineers… • Place ethics and morals above all else • Are team players • Follow a deterministic design process • Follow a schedule • Document their work • Never stop learning
Module Organization: The Design Process • Identify a need, who is the “customer” • Establish design criteria and constraints • Evaluate alternatives (systems or components) • Build a prototype • Test/evaluate prototype against criteria • Analyze, “tweak” (), redesign (), retest • Document specifications, drawings to build
Engineering Design ProcessBackup Chart • Identify a need • Establish design criteria and constraints • Evaluate alternatives • Build prototype • Test/evaluate against design criteria • Analyze, redesign, retest • Communicate the design
Begins with a recognition of need for a product, service, or system During the idea phase encourage a wide variety of solutions through brainstorming, literature search, and talking to users Best solutions are selected for further refinement Models or prototypes are made and problems that arise may require new ideas to solve and a return to an earlier stage in the process Finally drawings are released to manufacturing for production Design is an Iterative Process
Engineering Design Defined The crux of the design process is creating a satisfactory solution to a needHarrisberger
Problem Definition/ Specifications Data & Information Collection Development of Alternative Designs Evaluation of Designs/ Selection of Optimal Design Implementation of Optimal Design Engineering Design Process Customer Need or Opportunity Source: Accrediting Board For Engineering and Technology
Primary Design Features • Meets a need, has a “customer” • Design criteria and constraints • Evaluate alternatives (systems or components) • Build prototype (figuratively) • Test/evaluate against test plans (criteria) • Analyze, “tweak” (), redesign (), retest • Project book: record, analyses, decisions, specs
Step 1: Need • Have a need, have a customer • External vs internal; Implied vs explicit • Often stated as functional requirement • Often stated as bigger, cheaper, faster, lighter • Boilerplate purpose: The design and construction of a (better____something)_____ for (kids, manufacturing, medicine) to do __________.
Step 2: Criteria & Constraints “Design criteria are requirements you specify for your design that will be used to make decisions about how to build the product” Aesthetics Geometry Physical Features Performance Inputs-Outputs Use Environment Usability Reliability
Some Design Constraints • Cost • Time • Knowledge • Legal, ethical • Physical: size, weight, power, durability • Natural, topography, climate, resources • Company practices
Activity/Demonstration • Product index cards • Pair up as customer-designer • Variation on 20 questions • Identify some design criteria and constraints for sample products • Discuss
Step 3: Evaluate Alternatives • Needs best stated as function, not form • Likely to find good alternatives for cheapest, fastest, lightest, and encourage discovery • Research should reveal what has been done • Improve on what has been done • Play alternatives off criteria and constraints • Brainstorming helps
Best Design • Choose best design that meets criteria • Demonstrate tradeoff analyses (among criteria and constraints) are high quality • Cost (lifecycle) is always consideration • Resist overbuilding; drives complexity, cost, time, resources A quality design meets customers expectations!
Step 4: Prototype • Prototype is implementation of chosen design alternative • It is a proof of design, production and suitability • Prototypes are often cost prohibitive: Models and simulations may suffice • Quality design does not include redesigning a lot of prototypes
Prototype Prototype picture of 747
Step 5: Test it Well • Test and optimize design against constraints and customer expectations. • Create a test plan showing how to test • Test in the conditions of use • Good test plan shows what test, expected results how to test, and what analyses will be. It relates to specification requirements • e.g. test plan for light bulb (activity)
Activity: Light Bulb Test Production assembly-time-demonstration Robustness-vibration, temperature-test article Life-hours-statistical sample Duty cycle-count on/off-prototype Brightness-lumens-measure Packaging-drop test-do last Base fit-yes/no-first article demo
Test Results Successful Test:Satisfying Test Failure:Priceless
Step 7: Documentation • Project data book A complete record All key decisions Good drawings Test plans Results Conclusions Things learned
Draw a Good Picture • Drawings for project notebook, application, display • Photos, sketches, CAD 2-D or 3-D • Show assembly, components, materials