Engineering and Science

Purpose and Nature Science is the search for knowledge and understanding Technology is the application of knowledge to satisfy human needs They are both creative problem solving methods!

Engineering is... “ … the profession in which a knowledge of mathematics and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to utilize, economically, the materials and forces of nature for the benefit of mankind." ( ABET)

Processes Compared Scientific Method Engineering Design Process Why? Knowledge Need Thing Specification

The Rest of Engineering

Engineers Drive Trains! The distinctions among science and engineering and technology are often arbitrary Engineering design, product testing, engineering analysis, scientific method are all creative, problem solving processes However, schools teach Engineering using the scientific process with very little hands- on or applied learning activities Students are often left wondering what Engineers really do

Engineering Design Process Description

Engineering Design Defined The crux of the design process is creating a satisfactory solution to a need Harrisberger

The Engineering Design Process? Customer Need or Opportunity Implementation of Optimal Design Evaluation of Designs/ Selection of Optimal Design Development of Alternative Designs Data & Information Collection Problem Definition/ Specifications Source: Accrediting Board For Engineering and Technology

Engineering Design Define a need Develop design criteria Search literature to see what has been done Prepare preliminary designs Build and test a prototype Redesign and retest as necessary Source:

Dissecting the Engineering Design Process

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 __________.

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 CostTimeKnowledge Legal, ethical Physical: size, weight, power, durability Natural, topography, climate, resources Company practices

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

Simulation

Best Design Choose best design that meets criteria Demonstrate tradeoff analyses (among criteria and constraints) is high quality Cost (lifecycle) is always consideration Resist overbuilding; drives complexity, cost, time, resources A quality design meets customers expectations!

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

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

Test and Redesign

Test Results Successful Test: Satisfying Test Failure: Priceless

Project book 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

Product Sketches

Other Drawings

Model Abstract Engineering goal ~ purpose ~ need Design and construction of gum-repelling shoe Design and construction of gum-repelling shoe Design and evaluation criteria Procedures and equipment Alternatives, solution, prototype features Alternatives, solution, prototype features Test plan ~ test results Conclusions Met need? Why not? Changes? Knowledge? Met need? Why not? Changes? Knowledge?

Summary

Processes Compared HypothesisExperimentConcludeNeed Criteria, constraints Alternatives Build prototype Test, modify, retest Specification “The crux of the design process is creating a satisfactory solution to a need”

Design Features 1.Meets a need, has a “customer” 2.Design criteria and constraints 3.Evaluate alternatives (systems or components) 4.Build prototype (figuratively) 5.Test/evaluate against test plans (criteria) 6.Analyze, “tweak” ( ), redesign (  ), retest 7.Project book: record, analyses, decisions, specifications

Summary: A Superior Project A clear and relevant need from customer Research what’s been done before: don’t make theories out of facts Enough criteria to develop alternative designs and perform design trades Prototype built after best design chosen Test prototype as it will be used Comprehensive project book, good specs

Avoid These Pitfalls No need, no end product Analysis as a product Turning facts into questions with hypotheses Reverse engineering the process Ah ha!, gadgetry, kits Demonstrations, product testing Testing without asking the user No analysis of prototype test results

Key Terms Define in context and summarize here.. PrototypeModelSimulationHypothesis Design criteria Design constraints

Activity: Design Criteria What should I test about a light bulb? Base fit-yes/no-first article demo Brightness-lumens-measure Life-hours-statistical sample Packaging-drop test-do last Robustness-vibration, temperature-test article Duty cycle-count on/off-prototype Production assembly-time-demonstration

Activity Teams define test requirements for a familiar thing such as MP3 Player, Cell phone, or clothing and report out to class

About the Scientific Method

Scientific Method(s) Be curious ResearchHypothesis Experiment, data Reach Conclusions Prepare report and exhibit Observe Do research Formulate hypothesis Design experiment Stop. Do application Conduct experiments Evaluate, conclusions Prep paper & exhibit Prepare abstract Source: Source: SCVSEFA Handbook

Hypothesis An educated guess Prediction of outcome That which can be measured and tested Cause and effect Example: if x is true, then y will happen To help answer “Why”?