ENG1000 Chapter 1: Introduction

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Engineering Design I

Chapter 1: Introduction

Richard Hornsey

Departments of Computer Science & Physics

Fall 2002

About Me

Ancient history

MA, MSc, DPhil, Oxford University

Hitachi Central Research Labs, Tokyo

Microelectronics Research Lab., Cambridge University

Electrical and Computer Engineering, University of Waterloo,

1994 - 2001

Research areas:

 electronic materials, manufacture of microelectronic devices nanostructures thin-film electronics integrated sensors

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Outline of Introduction

What is an Engineer?

What is Engineering?

Where is Engineering going?

Skills required by and Engineer

Engineering Design

The design process

Case study

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What is an Engineer?

R. Hornsey www.startrek.com

www.unitedmedia.com

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Other Engineers

Isambard Kingdom Brunel

R. Hornsey William Gates collections.ic.gc.ca

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Mechanical Engineering

Bombardier’s snowmobile

(1923)

R. Hornsey sol.brunel.ac.uk/~jarvis

Brunel’s Clifton

Suspension Bridge

(designed 1830)

Donald Smith and the

“last spike” (1885)

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Religious Engineering

Pyramids

(c. 2500BC)

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Stonehenge

(c. 2500BC)

Leaning tower of Pisa (1173)

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Military Engineering

http://abe.www.ecn.purdue.edu/~agenhtml/agenmc/china/images/scenery/gw0.gif

Great Wall of China

(200BC)

B-2 Stealth Bomber (1990s)

R. Hornsey http://www.airforce-technology.com/projects/b2/b21.html

medieval trebuchet

(1300s)

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Civil Engineering

Pont du Gard, France (20BC)

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CN Tower, Toronto (1976)

Petronas Towers

Kuala Lumpur (1998)

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Newer Engineering

Intel Pentium 4 www.mdrobotics.ca

Canadarm

R. Hornsey Confederation Bridge

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What differences?

What are the differences between the traditional and the newer forms of engineering?

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So … What is Engineering?

“I fix things; that’s what Engineers do.”

Chief Miles O’Brien, StarTrek Deep Space

Nine

Profession devoted to designing, constructing, and operating the structures, machines, and other devices of industry and everyday life

Discipline dealing with the art or science of applying scientific knowledge to practical problems

 better – it implies a scientific basis

 while acknowledging that there is an artistic component

 and that engineers solve practical problems

“Doing for seventy cents what any fool can do for a dollar” not precise, but sums up the economics

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Textbook Definitions

Association of Professional Engineers of Ontario (APEO)

“any act of designing … that involves third-party concerns … and that requires the application of engineering principles”

Professional Engineers Act, Ontario

1. any act of designing, composing, evaluating, advising, reporting, directing or supervising;

2. wherein the safeguarding of life, health, property or the public welfare is concerned, and

3. that requires the application of engineering principles, but does not include practising as a natural scientist.

Textbook for this course

“an innovative and methodical application of scientific knowledge and technology to produce a device, system or process, which is intended to satisfy human need(s)”

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Key Concepts

Engineering is a profession

 what does it mean to be a professional?

Engineering is legally regulated

 use of the title “Engineer” is restricted

Key words in these definitions

 design third-party concerns; safety and public welfare innovative methodical scientific knowledge; technology produce device, system, or process

Engineers Act serves to protect the public

 for more information on the Professional Engineers of Ontario (PEO), see http://www.peo.on.ca

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“Engineering” Designation

Canadian Council of Professional Engineers and Microsoft Corp. Agree on use of “Engineer” title

Ottawa, Ont., May 11, 2001 – After discussions with Canada’s engineering profession, Microsoft Corp. will advise Canadian holders of its MCSE certification not to call themselves engineers or use the full title Microsoft Certified System Engineers.

Microsoft’s decision should prevent Canadian holders of the MCSE certification from inadvertently breaking provincial and territorial laws, which protect the public by restricting the use of the titles “engineer” and “engineering” and the practice of engineering in Canada to licensed professional engineers. It should also ensure that the engineering profession’s licensing bodies will not be required to take enforcement action against MCSE holders who mistakenly use the title engineer or otherwise hold themselves out as having been qualified to practice engineering.

“We are very pleased by Microsoft’s decision,” said Marie Lemay, P.Eng., CEO of the Canadian Council of Professional

Engineers (CCPE). “Microsoft has demonstrated corporate leadership by acting in the best interest of the MCSE community.

Holders of the MCSE certification are not licensed or regulated by the engineering profession. If they mistakenly use the titles

“engineer” and “engineering” the provincial or territorial engineering associations/order would have to take enforcement action against them. Its decision is good for the information technology industry, good for MCSE holders, and good for the engineering profession.”

The engineering profession, represented by CCPE and several provincial engineering regulatory associations, met with

Microsoft in Seattle late last year to explain the legal issues surrounding the use of the title “engineer” in Canada, and to ask the corporation to stop referring to holders of the MCSE credential as engineers. Canadian MCSEs have received certification as Microsoft Certified Systems Engineers, which could lead them to mistakenly misuse the title “engineer.”

“We are very pleased to have reached an agreement with the engineering profession and to support it,” said Anne Marie

McSweeney, the acting Director of Microsoft Certification and Skills Assessment. “It opens the door for closer cooperation among all organizations in the information technology industry and the engineering profession in Canada. As the Microsoft credentials continue to evolve, it is our goal to ensure they maintain the highest level of relevance to the industry and represent leaders in cutting-edge technology.”

Microsoft is currently researching alternatives for the MCSE credential worldwide, which could result in a new name for the credential later this year.

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Whither Engineering?

Based on out definitions, is this engineering?

Or this?

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Top 10 Skills of an Engineer

From the text book:

1.

2.

3.

4.

5.

6.

7.

Problem-solving skills

Effective communication skills

Highly ethical and professional behaviour

Open mind and positive attitude

Proficiency in math and science

Technical skills

Motivation for “lifelong learning”

8.

9.

Knowledge of business strategies and management practices

Computer literacy

10.

Understanding of world affairs and cultures

Be good at everything!

The engineering profession is changing

• no longer do people stay with one company the above skills ensure that an engineer remains flexible

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Accreditation Board for Engineering and

Technology (ABET)

Engineering programs must show that their graduates have:

 an ability to apply knowledge of mathematics, science, and engineering an ability to design and conduct experiments, as well as to analyse and interpret data an ability to design a system, component, or process to meet desired needs an ability to function on multi-disciplinary teams an ability to identify, formulate, and solve engineering problems an understanding of professional and ethical responsibility an ability to communicate effectively the broad education necessary to understand the impact of engineering solutions in a global and societal context a recognition of the need for, and an ability to engage in life-long learning a knowledge of contemporary issues an ability to use the techniques, skills, and modern engineering tools necessary for engineering practice.

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Half-life of Knowledge

Half-life is the time after which half of our (technical) knowledge is obsolete

~12 years in 1940

~5 years in 2000

~3 years for software professionals long half-life knowledge

Fundamentals time e.g. science & math, communication, creativity, process short half-life knowledge time

Application Specific e.g. software packages, exam cramming

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What is “Design”?

From Oxford English Dictionary

 to make the plans and drawings necessary for the construction of (a building, ship, machine, etc.), which the workmen have to follow out from Latin, to mark out, from de- + signare to mark

Engineering Design

 is the systematic, intelligent generation and evaluation of specifications for artifacts whose form and function achieve stated objectives and satisfy specified constraints (Dym & Little) how is this different from the definition of “engineering”?

Key words

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 systematic generation and evaluation specifications, stated objectives artifacts form and function constraints

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Engineering Design is a Process

The underlying philosophy of this course is that engineering design is a process that can be learned

It is this process that distinguishes an engineer from an inventor

 indeed, good professional practice requires that the appropriate process be followed

Such management practices are being standardised in such generic standards as ISO 9000

“The ISO 9000 family of standards represents an international consensus on good management practices with the aim of ensuring that the organization can time and time again deliver the product or services that meet the client's quality requirements. These good practices have been distilled into a set of standardized requirements for a quality management system, regardless of what your organization does, its size, or whether it's in the private, or public sector.”

R. Hornsey this is not specifically for engineering, but the same idea applies

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Design Process Cycle

From textbook: Needs assessment

(Evaluation) Implementation

Problem formulation

Abstraction and synthesis

Analysis

Other books use slightly different models, e.g. Dym & Little

1.

2.

3.

4.

5.

6.

7.

Client Statement

Problem Definition

Conceptual Design

Preliminary Design

Detailed Design

Design Communication

Final Design

Are these the same? Which do you prefer?

The 6 steps in the cycle are well described in the text ( §1.2)

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Needs Assessment

Identify the objectives and/or needs

 may be supplied by the client may require ‘education’ of the client

Who will benefit from the solution? How?

What solutions, if any, already exist?

 strengths and weaknesses?

What are the constraints?

 may be apparent or hidden

How will you know if the needs have been met?

 testability, design for test verification manufacturability

For example, we are asked to build an aeroplane

(based loosely on case studies of the Wright brothers in Ch.1 of text) it must be capable of powered flight

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Unanticipated Constraints - Challenger

An unanticipated constraint in the Chellenger design

‘O’-ring seals do not seal effectively at low temperatures

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Problem Formulation

Define the ‘real’ problem

 re-interpret the objectives in the light of what is possible

The goal is to break down the problem into a set of design objectives which can lead to a full solution

 check that the sum of the parts still equals the whole, i.e. the individual steps together solve the original problem

For our aeroplane

 require enough lift

 must overcome drag need a low-mass engine must have enough control (pitch, roll, yaw)

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Abstraction and Synthesis

Develop general methods for solving the problems, including alternatives

Each of the problems must be tackled methodically, based on

 experience technical knowledge creativity input from others

If necessary, additional knowledge should be gained from published material or from experimentation/theory

For example

 determine how the the drag and lift are affected by the shape and area of the wing, hence propose appropriate wing geometries find someone to build a lightweight engine to your specifications test a number of control strategies on un-powered gliders before designing the final version

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Approximations

The world is not an ideal place

 non-idealities lead to very complex – and not necessarily solvable – calculations

 even ideal situations have no straightforward solution e.g. the motion of a pendulum with just one extra joint is chaotic

However, engineers must find a workable solution

Sometimes a brute-force approach is used, such as numerical simulation

 but this is still only as good as the knowledge used to construct the simulator

Typically, the skill of an engineer is to determine which

approximations to use in order to reach an acceptable solution

 e.g. Sydney Opera House

R. Hornsey the architect originally wanted parabolic roofs but the stress calculations were so complex that engineers eventually substituted arcs of circles

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Analysis

Determine which of your designs is best

 technically economically ethically, environmentally to manufacture (linked to economics) for product life cycle for human factors satisfies the customer

Construct prototypes to evaluate close contenders

 the Wright brothers made numerous revisions and modifications to their gliders based on trials of the prototypes

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Implementation and Evaluation

Build it and sell it!

Typically, pre-production models will be tested before fullscale manufacture

 by the customer by focus groups by interest groups, e.g. beta testing of software

The design process is iterative

 i.e. it repeats continuously, (hopefully) approaching the optimum solution

How do we know that the solution is getting more optimal?

 evaluation, feedback from customers, litigation

 for mass produced products, there is more feedback, but the consequences of an error are larger e.g. recent Bridgestone-Firestone tire recall

It is very expensive if it is the customer who finds the fault in your product

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Flaws in Evaluation

The Pentium Bug

 a subtle fault which appeared in 1994 that could produce significant errors in mathematical calculations

Intel initially responded that only people doing ‘serious’ math would get a replacement company eventually gave in under intense pressure and offered replacements for everyone

New Intel slogans

Q: How many Pentium designers does it take to screw in a light bulb?

A: 1.99995827903, but that's close enough for non-technical people.

At Intel, quality is job 0.999999998.

http://www.maa.org/mathland/mathland_5_12.html

Law of ten

 cost of catching a mistake increases tenfold at each stage

 concept, schematic, layout, manufacture, packaging, verification, customer

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Summary

Engineers are highly skilled and versatile professionals

 with understanding both of the technical theory and the methods for solving problems

Problem solving is structured

 several different methodologies are possible but the outcome is similar

This combination makes the professional engineer different from both the technologist and the inventor

We concluded this introduction with a brief overview of each of the stages of the design process

These stages will be examined in detail in the remainder of the term

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Other Books to Read

C.L. Dym & P. Little, "Engineering Design: A Project-Based

Approach", Wiley, 2000, ISBN 0-471-28296-0

P. Dominick et. al., "Tools and Tactics of Design", Wiley, 2001,

ISBM 0-471-38648-0.

M. Horenstein, "Design Concepts for Engineers”, Prentice

Hall, 1999, ISBN 0-13-081369-9

C. Fleddermann, "Engineering Ethics", Prentice Hall, 1999

ISBN 0-13-784224-4

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Homework

Read and understand the section on report writing in textbook

( §1.5)

Read the case studies at the end of Ch.1

Chapter 1 problems

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