total design: a methodology for product design

© 2001 Miguel A. Torres

Total Design: A Methodology for Product Design

� Introduction to the Concept of Total Design

� Problem Definition-The Brief-The Product Design Specification (PDS)

� Conceptual Design� Concept Evaluation

-Rating/Weighting-Controlled Convergence Method

� Conclusions

Part I

Part II

Prepared by: Miguel A. Torres, Ph. D., P.E.Associate ProfessorDepartment of Mechanical EngineeringUniversity of Puerto Rico at Mayaguez


Case Study: IN-LINE SKATESGraphic Design

Industrial Design

Ergonomics

Manufacturing

Plastics Engineering

Mechanical Design

Packaging Engineering

Technical WritingFluid Design

Market Analysis


Heat Transfer

Industrial Design

Case Study II: The Personal Computer

Graphic Design

Software Engineering

Plastics Engineering

Electromechanical Design

Manufacturing

Packaging Engineering

Ergonomics

Mechanical Design

Technical Writing


But, How does this fact compares with the way we have been educated as engineers?

Conclusion:� A typical product is made up of many technological as well as non-technological components.�

Material Sciences

Controls

Electronics

Law Marketing

Finance

Psychology

Ergonomics Machine Design

Engineer

Diploma


The engineering degree has been broken down in manageable packages which we call COURSES.

Unfortunately, you will see that this represent the professional divisions of

most universities and indeed INDUSTRY.

Manageable for the STUDENTS and for the TEACHER

INELINELICONICON

INCIINCI

INMEINME

ESPAESPA

ADMIADMI

ININININ


TOTAL DESIGN

Total Design is a systematic methodology to achieve integration of the technological as well as non-technological subjects material with the goal of creating successful products and processes.

Customer Product

TOTAL DESIGN is distinguish from �partial design� in which TOTAL DESIGN requires the input from people of many disciplines, both engineering and non-engineering, in a mix that is almost unique to the product under consideration.


Product Design Core

Market

Specifications

Conceptual Design

Detail Design

Manufacturing

Sales


ManufactureCompetition

Costing

Info

Control

Electronics

Electrical StressHydraulics

MechanismsMechanical Stress

Power Systems

Vibrations

Surface Amount

Quality Control

Information

Technology-Dependents Tools

Product Design Core

Market

Specifications

Conceptual Design

Detail Design

Manufacturing

Sales


ManufactureCompetition

Costing

Info

Control

Electronics

Electrical StressHydraulics

MechanismsMechanical Stress

Power Systems

Vibrations

Surface Amount

Quality Control

Information

Technology-Dependents Tools

Product Design Core

Market

Specifications

Conceptual Design

Detail Design

Manufacturing

Sales Technology-Independent Tools

Competition Analysis

Info Acquisition

Synthesis

Concept Selection

Data handling

Optimization

Cost patterns

Market Trends

Info


MarketMarket

Specifications

Conceptual Design

Detail Design

Manufacturing

Sales

All design starts with a needthat, when satisfied, will fit into an existing market or create amarket of its own.

The outcome of this designactivity is a statement of needor a �brief�.


MarketMarket

Specifications

Conceptual Design

Detail Design

Manufacturing

Sales

All design starts with a needthat, when satisfied, will fit into an existing market or create amarket of its own.

The outcome of this designactivity is a statement of needor a �brief�.

Example:Design a machine for material handlingcapable of maneuvering over rough terrain


SpecificationsMarket

Specifications

Conceptual Design

Detail Design

Manufacturing

Sales

PDSChanges D/W Requirements

D Throughput (mixed Flow) max... 10 l/min. @ 2 bars

D max.. Pressure 10 BarsW Temp. of Water standard 60ºCD To fit hose basinD Light Operation (Children)D No Extra energyW Smooth, easily cleaned contour,

no sharp edgesChanges D/W Requirements



no sharp edges

Changes D/W RequirementsD Throughput (mixed Flow) max..

10 l/min @ 2 barsD max. Pressure 10 BarsW Temp. of Water standard 60ºCD To fit hose basinD Light Operation (Children)D No Extra energyW Smooth, easily cleaned contour,

no sharp edges

The outcome of this design activityis the Product Design Specification


Changes D/W Requirements ResponsibleD Throughput (mixed Flow) max.

10 l/min. @ 2 barsD max. Pressure 10 BarsW Temp. of Water standard 60ºCD To fit hose basinD Light Operation (Children)D No Extra energyW Smooth, easily cleaned contour,

no sharp edges

The General Structure of the PDS

DATE:_______Title:_________________


The Product Design Specification

Market

Specifications

Conceptual Design

Detail Design

Manufacturing

Sales

PDSChanges D/W Requirements



no sharp edges

Changes D/W RequirementsD Throughput (mixed Flow) max...

10 l/min. @ 2 barsD max.. Pressure 10 BarsW Temp. of Water standard 60ºCD To fit hose basinD Light Operation (Children)D No Extra energyW Smooth, easily cleaned contour,

no sharp edges

Changes D/W RequirementsD Throughput (mixed Flow) max..

10 l/min @ 2 barsD max. Pressure 10 BarsW Temp. of Water standard 60ºCD To fit hose basinD Light Operation (Children)D No Extra energyW Smooth, easily cleaned contour,

no sharp edges

�Controls the rest of the design activities.� It is Dynamic.�It is legal document.


�To be successful, you have to be systematic and thorough, paying meticulous attention to detail from the beginning to the end of the design activity.�


Characteristics of the Product Design Specification (PDS):

� The PDS is the fundamental control mechanism that allows this success to manifest itself.

� The PDS must be comprehensive and unambiguous.� At the end of the design process the product must be

balanced with the PDS.� Poor PDS leads to poor design that will fail in the

market.� Good PDS does not guarantee good design but make

the goal more attainable.� PDS set the design in context which are a

comprehensive set of constrains.

PDS


The Contents of a PDS: Performance

Webster�s Dictionaryper� for �mance \pe(r)-�fo r-men(t)s\ n(15c)1a: the execution of an actionb: something accomplished: DEED, FEAT2: the fulfillment of a claim, promise, or request: IMPLEMENTATION3a: the action of representing a character in a playb: a public presentation or exhibition Ea. benefit performance 4a: the ability to perform: EFFICIENCYb: the manner in which a mechanism performs engine performance 5: the manner of reacting to stimuli: BEHAVIOR6: linguistic behavior - compare COMPETENCE 3- per for ma to ry \-me-, to r -e , -, to r-\ adj

per� for �mance \pe(r)-�fo r-men(t)s\ n(15c)1a: the execution of an actionb: something accomplished: DEED, FEAT2: the fulfillment of a claim, promise, or request: IMPLEMENTATION3a: the action of representing a character in a playb: a public presentation or exhibition Ea. benefit performance 4a: the ability to perform: EFFICIENCYb: the manner in which a mechanism performs engine performance 5: the manner of reacting to stimuli: BEHAVIOR6: linguistic behavior - compare COMPETENCE 3- per for ma to ry \-me-, to r -e , -, to r-\ adj

�Performance should be fully defined, e.g., how fast, how slow, how often, continuously vs. discontinuous, energy requirements- electrical, hydraulic vs. pneumatic, tolerances, etc.�


�A common failing in specifying performance is to ask for the ultimate, rather than which is obtainable from economical point of view.�

±0 tolerance-> ∞$


The Contents of a PDS: Environment� temperature range� pressure range (altitude)� humidity� shock loading (gravity forces) � dirt or dust - how dirty? - how

clean?� corrosion from fluids - type of fluid

or chemical� noise levers� insects� vibration� type of labor or person who will

use the equipment - likely degree of abuse?

� any unforeseen hazards to customer, user or the environment - for example inclusion of CFCs?


The Contents of a PDS: Environment

� During manufacturing -exposure to cutting fluid, solvents, fluxes, acids, etc.

� During storage - in the plant� During assembly - assembly

forces, contamination from sweating hands?

� During packaging� During transportation� During storage - at a wholesale�s

warehouse� During display� During use

These may occur at the following stages:


PDS: Guide lines

� The PDS is a control document.� It is a use document.� Never write a PDS in an essay format.� From the beginning, try to quantify

parameters.� Always date the document and to an

issue number.� Clearly document amendments.

PDS


Conceptual Design

� It is the phase of design primarily concerned with the generation of solutions to meet the stated need, i.e., the PDS.

Conceptual Design is a �Synthesis�

Market

Specifications

Conceptual Design

Detail Design

Manufacturing

Sales


Conceptual Design

Conceptual Design has two major components:

1. The generation of solutions to meet thestated need, i.e., the PDS.

2. The evaluation of these solutions to selectthe one that is must suited to match the need.

Market

Specifications

Conceptual Design

Detail Design

Manufacturing

Sales


Conceptual Design1. The generation of solutions to meet the PDS.

In order to generate solutions or ideas to solve a givendesign problem you must be �creative�

Idea!!!


Conceptual Design1. The generation of solutions to meet the PDS.

Yes but how do I become �creative�?

?

Everybody is creative. All we need to do iswatch out for �Mental Blocks�


Conceptual DesignRecognizing and dealing with Mental Blocks

�The Right Answer�



�That is not Logic�

Finish



�Follow the Rules�



�Be Practical�



�Play is Frivolous�



�That is not my area�



�Avoid Ambiguity�

Ambiguous



�Don�t be foolish�



�To err is wrong�



�I�m not Creative�


Idea Generation: Tips

Idea!!!


� Concepts are best generated by individuals



Conceptual Design

◆ Concepts are best generated by individuals

◆ Avoid at all cost the temptation to �cut and run� and start engineering and developing the ideas further.




� Avoid at all cost the temptation to �cut and run� and start engineering and developing the ideas further.

� You need as many ideas as you can.




� Avoid at all cost the temptation to �cut and run� and start engineering and developing the ideas further.

� You need as many ideas as you can.

� Stay within the laws of physics.



Concepts are best generated by individuals

Avoid at all cost the temptation to �cut and run� and start engineering and developing the ideas further.

You need as many ideas as you can.

Stay within the laws of physics.Always keep the PDS as a

reference.


PDS


Conceptual DesignIdea Generation: More Tips

Use the following techniques:

+ =

1. Brainstorming

2. Analogies3. Combinations


Conceptual DesignAn idea is not an idea if you cannot communicate it.

�3D Sketching�Diagrams�Circuit Diagrams�Block Diagrams�World Description�Ladder-logic diagrams�Mathematical Expressions�Analytical Drawings

Note: Concepts or ideas must be titled, numbered andionized so they can be cross referenced later.


Conceptual Design

Concepts generated at this phase should never bearbitrarily discarded as not been good. Particularly because a third party does not like them.

�Gut-feeling� design is out of the question.


� This criteria comes from the PDS.

� This is carried out in groups (never along)

� It should be written down.

To effectively evaluate a concept, an agreed set of criteria is needed.


The Controlled Convergence MatrixA methodology for sorting out ideas.

Example:

Brief: �Design a car horn.�

PDS:


D Able to Produce 105-125 DbAD Able to Produce 2000-5000 HzD Corrosion, erosion and water resistant.D Resistance to vibration, shock and acceleration.D Temperature range -50°F to 200°FD Time response: 250 msec.D Small number of stages.W Power Consumption < 35 WW Low MaintenanceW Weight: < 2 lbs.W Size: < 6x6x6in.W Low num. parts.D Life in service: >10 yearsW Manuf. Cost: < $3.00D Easy installationW Shelf Life: 20 years

Concept EvaluationThe Controlled Convergence Matrix

D/W Criteria

PDS for a Car Horn



CriteriaAble to Produce 105-125 DbAAble to Produce 2000-5000 Hz

Corrosion, erosion and water resistant.Resistance to vibration, shock and acceleration.

Temperature range -50°F to 200°FTime response: 250 msec.

Small number of stages.Power Consumption < 35 W

Low MaintenanceWeight: < 2 lbs.Size: < 6x6x6in.

Low num. parts.Life in service: >10 years

Manuf. Cost: < $3.00Easy installation

Shelf Life: 20 years

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Sum +�sSum -�s

Sum S�s

Ideas

D

A

T

U

M


The Controlled Convergence Matrix

Able to Produce 105-125 DbAAble to Produce 2000-5000 Hz







Shelf Life: 20 years

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Sum S�s

Concept EvaluationCriteria

Sum +�sSum -�s

Ideas

D

A

T

U

M

S

S

-

--

--

-

S

S

S

S

S

S

S

S



CriteriaAble to Produce 105-125 DbAAble to Produce 2000-5000 Hz







Shelf Life: 20 yearsSum +�sSum -�s

Sum S�s

Ideas

D

A

T

U

M

S

S

-

--

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NoT

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ALUATED

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295

817

394

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3121

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286

2131

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493

1 2 3 4 5 6 7 8 9 10 11 12 13 14


Remember that:The wrong choice of concept in a given design situation can rarely, if ever, be

recouped by brilliant detail design.

total design: a methodology for product design

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