Functionally Efficient Conceptual Design and Innovation Tools

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Original Article Proceedings of Virtual Concept 2006Playa Del Carmen, Mexico, November 26 th December 1st, 2006

Functionally efficient conceptual design and innovation tools

Martin E. Baltazar-Lopez, Jorge D. Flores-Porras, Eric F. Zenteno-Cardoso, Marco A. Miranda Ramrez

Centro Nacional de Investigacin y Desarrollo Tecnolgico, CENIDET

Prol. Palmira Esq. Apatzingan, Cuernavaca, Mor. 62240, Mexico.

Phone/Fax 52 777 312 76 13

E-mail : {baltazar, dflores05m,eric05m,mamr05m}@cenidet.edu.mx

Abstract: A design methodology founded on the researchwork done at the Institute for Innovation and Design in

Engineering, has been applied to enhance the ability to designand innovate of neophyte engineers at National Research and

Technological Development Centre (CENIDET) in Mexico.

This methodology is based on the cognitive skills of

abstraction, critical parameter identification, and questioning in

order to obtain a functionally efficient conceptual design.

Besides of teaching the design process to novice designers, the

methodology inspires in them a design philosophy which

enables them to perform engineering effectively andinnovatively in any area of specialty. Some examples of this

design philosophy are presented.

- However, by using a specific methodology, some times this

idea of getting industrial expertise and industrial problems

can be substituted for a solution of an everyday problem,based on the fact that not all the engineering problems come

from industry, being this more accessible for students,

nevertheless not less technically-challenging projects, and

making these solutions of a real need a good starting point of

their engineering design practice, some times those solutions

have risen interest from industrial partners.

Key words: Design methodology, Functional structure,

abstraction, Innovation.

1- Introduction

When teaching engineering, the process of learning through

real problems is a common practice. In some cases, in

undergraduate curricula it is necessary to have exposure to

industrial problems particularly on the last semesters of the

course of study in which industrial partners provide some of

their problems and industrial exposure first to the faculty and

then to students as a form of knowledge and expertise. Faculty

work with students to provide the information back to the

industrial partners as a form of Technical expertise and designspecific problems and thus as a solutions in which students are

exposed to the design process, they can get real results andbecome potential employees for industrial partners.

- In reality, this approaching of Industry and schools, as partners

to solve problems, in Mexican institutions is very incipient.

- In the mechanical engineering department of CENIDET, one

of the goals is to exposure the students to real engineering

practice. This is not always an easy task. In part because there

is a lack of confidence from possible industrial partners

because there is not such culture of University-Industry

partnership in Mexico.

2- The Methodology

Research evidence has shown that engineering design is a

process that can be developed and imparted to engineers

[PB1,UE1,U1,F1,S1]. Also other research studies shows thatcertain differences exist between experienced and novice

designers [G1,LS1]. Experienced designers come up with

innovative solutions quickly in comparison to novicedesigners because they first identify and then attack core

issues of a problem while neophyte engineers try to look at

existing-solution schemes or model dependent solutions

causing fixation of thinking and thus blocking the innovative

process.

In CENIDET we try to use those research findings to

increase our understanding of the design process as well as

effective means for teaching that process. The conceptualdesign methodology used is based on the techniques taught at

Texas A&M Universitys former Institute for Innovation and

Design in Engineering (IIDE) [B1,KB1] which provided to

industry continuing education customized workshops on

design innovation.

The core of this approach is a design philosophy based on

Abstraction, Critical Parameter Identification, and

Questioning.

The aims of the methodology are:

To provide an understanding of the creativeprocesses whereby the effect of a product can be

evaluated

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Virtual Concept 2006 Functionally efficient conceptual design

Figure 1: Abstraction Process.

To provide an understanding of innovation not only in

an industrial context but in every day life

To introduce a number of innovation techniques,

particularly based on abstraction and questioning

To introduce a number of advanced design techniques

to enable the innovation process to be executed andmanaged .

Once the students are familiar with the methodology, they can

perform design effectively and innovatively in any area of

specialty.

The core of the methodology is formed by three skills: theability to think on an abstract level; the ability to identify

critical parameters; and the ability to question.

2.1- Abstract level thinking

Novice design engineers try to get related solutions while

experienced designers get innovative solutions based on

abstract thinking on analyzing the core issue of a problem.

Abstraction is the process by which a perceived need is

progressively transformed from a colloquially expressed

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statement into a functionally precise definition, using

technically fundamental terms. This has been identified as one

of the key skills required for a designer.

The importance of abstraction in increasing the insight that the

designer has into the problem and simultaneously expanding

the solution space that can be explored. The abstraction process

to achieve the required level of abstraction for a given problemstatement is summarized in Figure 1.

Answering yes to all of the questions in Figure 1, can be

used to evaluate whether abstraction has been achieved to the

required degree. The ultimate goal of abstraction is to

simultaneously increase the insight into the problem and

expand the solution domain, to obtain innovative and non-

traditional solutions.

In the process of abstraction a need statement evolves from a

colloquially expressed phrase to a technically precise sentence

in a more abstract form. The solution-specific details are

eliminated and the terms qualitative. Through abstraction, thefinal need statement should be simultaneously technically

precise, solution independent, general but not vague, and

allows a greater variety of possible solutions at the conceptual

stage.

2.2 Need Statement

Based on the definition of the word Design: the process of

creating a device or system to satisfy a need thus the most

important and one of the most critical parts in the design

process is to define a need statement. The need statement

should reflect the problem in question, and the implicit

constraints of the probable solution.

In general, an engineering design process starts with the

identification of a need. It then assists a designer to generate

solutions to that need, to develop and implement systems or

components, and concludes with satisfactory qualification

and testing of a prototype. This whole process involves

organizing and managing resources and people. Critical

factors such as cost, safety, reliability, aesthetics, ethics, and

social impact are also considered during the design process.

A need statement describes the design task and it is

composed of two parts: a) the main design function and b)

the main design constraint.

2.3- Critical Parameter identification

The Critical Parameter Identification is the next systematic

process by which a designer identifies the important issues in

a recognized need. Those issues can be physical, natural,

chemical, or mathematical concepts that are significant to the

need. The Critical Parameter Identification and Abstraction

processes go parallel, along with questioning. Again there isa difference on how experienced designers attack a problem

and quickly reach and address the core issue in the problem,

in comparison to neophyte design engineers. Thus it could

be said that the rapid and skillful identification of critical

parameters is a characteristic of a good design engineer.

Karuppoor, et al [KB1] show the process of abstraction and

how the need statement goes from a colloquial sentence to a

more precise one an also the associated critical parameter

evolves along with it at each stage of abstraction.

Figure 2 shows the actions involved in identifying the critical

parameters for the design. Critical parameters are limiting

conditions and gradients that address the change or a rate of

Figure 2: Actions involved in Critical Parameter Identification



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change of a variable. A critical parameter is often

determined by those limiting conditions at interfaces

between the functional requirements of the design and the

environment. Thus for an engineer it is not an easy task to

minimize these rates of change and at the same time

meeting the specified need.

2.4-Questioning

Along with abstraction and critical parameter

identification, questioning skills are required in a good

design. For instance, questioning the constraint helps

establish whether this is a real or a perceived constraint, or

one that is being artificially imposed.

Also by questioning it is possible to recognize the true

need and from there innovative solutions that would not

otherwise have been considered. This illustrates how the

process of questioning is a subtle, yet powerful tool, in

helping define the true need and opening up the solutionspace for further exploration.

The effective designer, by questioning needs andassumptions, makes a conscious effort to be innovative and

to not get fixated on certain ideas. Figure 3 shows the various

questions that should be asked in relation to the need. These

consist of the five W s (Why? What? ) and the H

(How?) along with the opposite corresponding negative

questions. The role of a designer at this stage is the one of atrue researcher trying to find technically reasonable

explanations by gathering of information and can use these

questions to fully explore the task and gain insight into the

true need. The question of How? encompasses all the other

questions and is, in a sense, the means through which the

answers to the Ws can be implemented.

By Questioning, the designers thoughts are directed into

new solution spaces and thus avoid fixation on existing

solutions enabling the designer to be innovative and to

consider issues that have not been thought of before and and

considering problems in new and different perspectives.

3-Functional Analysis

At this point of the design process it is necessary to have allthe design specifications written and organized. This is done

by the functional analysis. The functional analysis is carried

out by using a chart known as functional structure.

3.1-Functional Structure

Once a problem is declared into the need statement, several

ideas come up into place. A common practice is to write

down all those ideas however most of the times, those are not

organized in a consistent way.

The functional structure is a graphic way to organize and

classify ideas into functions, restrictions, constraints,

alternatives and concepts.

As its name implies the functional structure must clearly

specify the main function and also sub-functions that the

device being designed must perform. Also all possible

constraints that will limit our solution space. Thefunctions are organized in such hierarchical way that the

main function and main constraint are at the first level

after the need statement, which in turn would be the header

of the chart. Going down to next level are the sub-

functions and secondary constraints, at the lower levels are

the alternatives and finally the concepts. When forming

this functional structure a questioning process is carried

out.

TRUENEED

Why

What?

Where

Who

When

How?

Wh not?

What not?

Where

Who not?

When not?

How

Figure 3: Questioning process to get the true need.



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Figure 4: Function Structure

4-Conceptual Design

The design itself demands creativity making the engineersand designers in inventors. Also the design is an iterative

process making necessary to look upon alternatives when

striving for an optimal solution design. The design requires

attention to the details. In many cases the details make the

difference between success and failure.

How it is defined a design need is reflected in the

solutions. A good need definition allows the conception of

innovative solutions at the functional structure.

Design can be viewed as an iterative movement between

the two knowledge domains achieved through the use of

the two thinking modes, form concept space toconfiguration space and vice versa. The conceptual space

implies a generalization or abstraction of specific

information to fundamental concepts which in turn fosters

divergent thinking. On the other side, a particularization or

configuration of abstract principles or concepts fosters

convergent thinking. This it is necessary to count of a largesample of functional alternatives which eventually will

evolve into conceptually different solutions.

At the conceptual design it is necessary to have at least

three conceptually different alternatives. Understanding as

different those solutions which have fundamentally

different principles or physical effects

Also the keys for a good conceptual design can be

summarized as follows:

Identify the critical design issues early.

Start early in the design process.

Get divorced often.

Consider design alternatives at each stage

Consider fundamental principles.

Continually reexamine assumptions.

Also some activities are implicit in the conceptual design

Idea Generation

o Identify ideas.

Concept Development

o Develop three conceptually different and

viable solutions.

Concept Evaluation

o Evaluate the solutions against the need.

o Create a single design incorporating

good features.

5-Case Study

Handicapped people in Mexico who has the necessity to

use wheelchairs for mobility find out in many occasionsthe problem to bridge the gap over steps, curbs, and raised

landings that are not accessible or do not count on an



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appropriate ramp. Thus a necessity arises to design a

device to be able to transport a non-electrical wheelchair

from the inferior level to the step or curb and vice versa.

5.1-Need:

It is required of a device that allows people who use

wheelchairs to accede with autonomy to steps or

curbs that do not count on access ramp.

5.2-Constraints:

It must be a relatively simple mechanism

It has to be of low cost (in comparison to the price

of the wheelchair)

That can be operated easily by the handicapped

person

Adaptable to any non-electrical wheelchair.

5.3-Need Analysis, Important questions:

What is needed? It is required a device that allowsthe handicapped people who use wheelchairs to

accede to steps or curbs that do not count on an

appropriate ramp and without help from a third

person.

Why it is needed? Because handicapped people

cannot accede with autonomy to steps and curbs

without an appropriate ramp.

Who needs it? Handicapped or Injured people

who use wheelchairs that they require of

autonomy for mobility.

Where is it needed? In any place with unevenness

(standard height of step, curb or sidewalk) that

does not count on an access ramp

When it is needed? At the moment that the

people mentioned above require to bridge the gap

over a step or curb.

How is it needed? It is required a relatively light

device, cheap and functional.

Is really needed? Yes, because not always there

are access ramps to the steps, curbs or sidewalks

or some person who can help.

5.4-Main function:

To raise wheelchair to a step, curb or sidewalk that is

not accessible.

5.5-Main restriction: With autonomy

5.6-True need: To raise a wheelchair, with

autonomy to a step, curb or sidewalk that is notaccessible.

5.7-Functional Structure

Based on the generic fuction structure of figure 4 and

the concepts in relationship to the functional analysis,

two functional structures were developed for this case.

Figure 5: Initial Functional Structure

To raise a wheelchair, with autonomy to a step, curb

or sidewalk that is not accessible

Allows horizontal

mobility.

Vertical displacements of

the wheelchair

Advance over flat floors

without raised landingsRaise a non

accessible step,

curb or sidewalk

Using a

motorized deviceUsing a manual

device

Maintain users

autonomy

Allowing mobility to user

without help of another

person



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Figure 6: Modified Functional Structure

5.6-Critical Parameter IdentificationAfter a rain storming some Critical parameters were

identified:

To raise/lower a wheelchair, with autonomy to a step,

curb or sidewalk that is not accessible.

Allows displacement

horizontal/vertical

Vertical displacements of

the wheelchair

Advance over flat floors

without raised landings

Raise/lower a non

accessible step,

curb or sidewalk

Using a

motorized deviceUsing a manual

device

Maintain users autonomy

Allowing mobility to user

without help of another

person

Allows horizontal

displacement for normal

mobility conditions

Hydraulic

SystemElectric

SystemMovable

armsTelescopic

RampManual

Lift

Height difference in steps, curbs or sidewalks(150 to 200mm aprox)

Maximum force to be exerted to themechanism

Dimensions

Weight

Cost

With the need statement and the information from critical

parameters a initial functional structure is developed. As

mentioned before a systematic way of organize ideas and

relate them to the solution as functions, constraints or

alternative concepts is necessary. A graphic way of doing

that is a organization chart known as Functional Structure

where the process of questioning is carried out at the sametime that the functions, sub functions and constraints are

arranged in a hierarchical levels from top to bottom. At the

lower level of the functional structure there should be at

least three conceptually different design alternatives, to be

evaluated at next design stage. The final functional

structure is obtained after an iterative process and

evolution of the need statement.

After analyzing all the involved aspects in functions and

constrains to obtain a suitable solution, the functional

structure evolves (and could be possible that the need

statement changes in the process) into a modified or

second functional structure. From the functional structureseveral conceptual alternatives emerged:

Telescopic Ramp

Hydraulic system

Movable arms

Electric system

Manual lift

In table I are shown all the considered conceptual

alternatives evaluated against a datum or reference. After a

matrix evaluation of the critical parameters of each of

those concepts it was determined that the hydraulicmechanism presented more advantages over the rest of the

alternatives, and also the movable arms mechanism had

several advantages over the ramp however when

considering manufacturing costs, these two options were

surpassed by the telescopic ramp mechanism. In the

process the conceptual design activities of Fig. 7 were

carried out.



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Figure 7: Layout of the Conceptual Design Activities

Critical

Parameter

Telescopic

Ramp

Hydraulic

System

Movible

arms

Electric

System

Manual

lift

Cost - - - -

Size + I - +

Weight - I - I

Manoeuvrability + + + +

Strength + I - I

Life cycle I - - I

Energy

consumption+ - - +

Maintenance - - - -

Manufacture - - - -

Total (+) 4 1 1 3

Total (-)

DATUM

4 5 8 3

Table I. Concept Matrix Evaluation



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Figure 8: Model of wheel and the telescopic mechanism

Based on these results, and applying de designer criteria,

the telescopic ramp was chosen to be developed as a

prototype.

5.7-Telescopic Ramp Mechanism

A wood model, Fig. 8, was constructed to illustrate the

movements involved in the mechanism. It consists of a

triple slider mechanism with a folding end ramp, deployed

in place with a single degree of freedom.

The ramp mechanism implemented on a wheelchair is

shown in Figure 9.

Because the simplicity of the mechanisms linkage, themanufacturing cost is low, making it affordable for the

majority of users of this kind of wheelchairs.

Figure 9: Ramp Mechanism implemented on the wheelchair



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6- ConclusionsThe philosophy from the Texas A&M Universitys former

Institute for Innovation and Design in Engineering (IIDE)

was used in a design methodology based on abstractioncritical parameter identification, and questioning to train

neophyte engineers in CENIDET Mexico, allowing them

to get the basic skills necessary to get quick innovativesolutions; at the same time having experience in solving

real engineering problems related to true needs which

otherwise do not have because of lack to exposure to

industrial problems. It was shown also that the

methodology can be used not only at industry but in every

day needs, which after the process could be adopted by

industry.

7- References

[B1] Burger C. P., Excellence in Product Development

through Innovative Engineering Design, EngineeringProductivity & Valve Technology, Valve Manufacturers

Association of America, Washington, DC, pp. 1-14, 1995.

[F1] French, M. J., Conceptual Design for Engineers, The

Design Council, London,1985.

[G1] Glegg, G.L.,The Design of Design, Cambridge

University Press, Cambridge, UK, 1969.

[KB1] Karuppoor, S. S., Burger C. P. and Chona R., A

Way of Doing Engineering Design, Proceedings of the

2001 ASEE Annual Conference, Albuquerque, NM, 2001.

http://www.asee.org/acPapers/01128_2001.PDF.[LS1] Leong, A. and Smith, R. P., An Observational

Study of Design Team Process: A Comparison of Student

and Professional Engineers, Proceedings of the 1997

ASME design Engineering Technical Conference,

Sacramento, CA, 1997.

[PB1] Pahl, G. and Beitz, W., Engineering Design: A

Systematic Approach, Springer Verlag, Berlin, 1996.

[S1] Suh, N. P., The Principles of Design, Oxford

University Press, New York., 1990.

[U1] Ullman, D. G., The Mechanical Design Process,

McGraw-Hill, New York., 2002.

[UE1]Ulrich, K. T. and Eppinger, S. D., Product Design

and Development, McGraw-Hill, New York,1995.

http://www.asee.org/acPapers/01128_2001.PDFhttp://www.asee.org/acPapers/01128_2001.PDF

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