GET130 Intro to Engineering Technology Fall 2015 J. Sumey 4: Engineering Design GET130 Intro to Engineering Technology Fall 2015 J. Sumey

What is Design? From Webster’s New Collegiate Dictionary: design n: a mental project or scheme in which means to an end are laid down; the arrangement of elements that go into human productions (as in art or machinery). design vb: to conceive and plan out in the mind; to devise for a specific function or end.

Design Example “create a device that safely transports people and goods through the air” http://www.terrafugia.com/

The Designer one of 3 roles in product design designs are motivated by a client designer must ascertain/clarify client wants and translate into an engineered product while maintaining obligations to the profession and to the public Client Designer User

Design Example 2 “create a personal mobile device to transport people who are unable to use their legs”

Engineering Design def: engineering design is a systematic, intelligent process in which designers generate, evaluate and specify designs for devices, systems or processes whose form(s) and function(s) achieve clients’ objectives and users’ needs while satisfying a specified set of constraints

ABET Definition of Design Engineering design is the process of devising a system, component, or process to meet desired needs. It is a decision-making process (often iterative), in which basic science and mathematics and engineering sciences are applied to convert resources optimally to meet a stated objective. Among the fundamental elements of the design process are the establishment of objectives and criteria, synthesis, analysis, construction, testing and evaluation. Engineering design features: development of student creativity use of open-ended problems development and use of modern design theory and methodology formulation of design problem statements and specification, consideration of alternative solutions feasibility considerations production processes concurrent engineering design detailed system description realistic constraints, such as economic factors, safety, reliability, aesthetics, ethics and social impact use of teams in solving problems and performing designs

Design Terminology form function means objective constraint metric requirement

Big Picture: Problem Solving problem: a perplexing question demanding settlement, especially when it is difficult or uncertain of solution. problem solving: a higher-order cognitive process (psychology) most complex of all intellectual functions the world is constantly in need of good problem- solvers! but problem solving failures are all too common…

Problem Solving why does problem solving fail? Claim Rebuttal inadequate information / ill-defined problems requirements need to be excruciatingly clear fear of making wrong decision but failure becomes success if we learn from our mistakes cost (time & energy) of solution generation and testing engineers/technologists must find time absence of effective problem-solving model false: models do exist limitations of the human mind ?

9 Dots Problem “Here's a pencil. Here's a piece of copy paper with nine dots on it. Without lifting the pencil or folding the paper, connect the 9 dots using 4 straight lines.” Can you solve this problem with three lines? With one? ●

Problem-Solving Models Scientific method used in natural sciences since 17th century consists of observation, measurement/experiment, hypothesis formulation/testing/refinement Engineering method used to mitigate negative effects of product or process failures has led to engineering design process

Engineering Design Process Overview of steps: problem identification research / problem definition brainstorm / develop possible solutions solution analysis / selection solution implementation test/evaluation of solution(s) communication / documentation refinement This is often an iterative process…

Engineering Design Process à la NASA Engineering Design Challenge Lunar Plant Growth Chamber (Link)

1: Problem identification Identifying problem / need Recognition of opportunities Collect & interpret information Organize/prioritize needs Document results typically results in requirements document text example: technology student consistently gets D grades on lab reports with no other instructor markings is this a problem? from student perspective? from instructor perspective? "students have the right to fail"

Example Requirements Performance/functionality Energy Reliability identify skin lesions with 90% accuracy measure within 1mm Energy battery-operated, avg. power consumption of 3 watts maximum current draw of 1 Amp Reliability operational 99% of the time mean time between failures (MTBF) of 5 years mean time to repair (MTTR) of 1 hour

2: Research Examine current state of the issues and existing solutions (if any) Explore alternative options using reference sources library: texts, periodicals, journals handbooks, building/safety codes datasheets / material safety data sheets (MSDS) Internet interviews etc.

2: Problem definition Clearly define problem & requirements client’s description is rarely detailed enough Establish metrics for design requirements to know how well solution meets objectives Identify constraints that pose limitations on solution Problem may then be clearly defined typically results in a specifications document

Constraints Economic Environmental Ethical and Legal Health and Safety Manufacturability Political and Social – FDA, language? Sustainability

3: Develop possible solutions Brainstorming various ideas – “conceptual design” Engage mathematic and scientific models and methods analyses, simulations, etc. Document / articulate possible solutions sketches, 2/3D, block diagrams, flowcharts Consider possible results/consequences of each Design solution strategy is then documented this results in a design document(s)

4: Selection Intelligently determine which solution or solutions best meet original requirements based on needs, requirements, constraints rank order if multiple Simplest and/or shortest solution may not always be the best! beware of overly frugal managers

5: Implementation “Make it so” obtain/acquire needed resources implement process build model build prototype create software

6: Evaluation Does resulting design solve problem? Requires testing against established metrics exhaustive testing sampled testing (SPC) data recording analysis Identify problems/shortcomings/etc. solution may need refined / adjusted

7: Communication Final documentation of design results May include a variety of components written report drawings / schematics oral report / presentation user’s manual production information

8: Refinement If problem/solution is on-going process or iterative in nature, the EDP may need repeated once appropriate refinements have be identified. May be required for ISO9xxx certification International Standards Organization quality control Academic equivalent is accreditation includes Continuous Improvement Plan (CIP)

“Simplified Version” Understand the problem Research/brainstorm solution High-level design block diagrams, flow diagrams, flowcharts Low-level design mechanical/assembly diagrams, schematics, call graphs Implementation Documentation Testing is done throughout

References “Engineering Design Process” ABET. http://abet.org http://en.wikipedia.org/wiki/Engineering_design_process ABET. http://abet.org Dym and Little. Engineering Design: A Project-based Introduction. New York: John Wiley, 2009. “ISO 9000” http://en.wikipedia.org/wiki/ISO_9000 “NASA Engineering Design Challenge” http://www.nasa.gov/audience/foreducators/plantgrowth/home