Evaluating the use of CAD systems in mechanical design engineering

DfciVVgy

HD28 .M414 no.

Zi%-

ALFRED

P.

WORKING PAPER SLOAN SCHOOL OF MANAGEMENT

CAD Systems in Mechanical Design Engineering

Evaluating the Use of

David

C Robertson

Thomas

WP

# 3196-90-BPS

J.

Allen January 1990

MASSACHUSETTS TECHNOLOGY 50 MEMORIAL DRIVE CAMBRIDGE, MASSACHUSETTS 02139 INSTITUTE OF

CAD Systems in Mechanical Design Engineering

Evaluating the Use of

David

C Robertson

Thomas

WP

# 3196-90-BPS

J.

Allen

January 1990

Abstract Despite the importance of and our long history with Computer- Aided Design (CAD) systems, our understanding of the systems is limited. The academic and trade literature provides little guidance on what organizational actions are necessary to

utilize

CAD

systems for

maximum

benefit.

CAD

systems are playing in the design engineering processes of different companies, field interviews were conducted at twelve Design engineers, managers, CAD support personnel, and others were companies. interviewed to understand the use of CAD systems for mechanical design engineering. The result of the field research is the conclusion that managers view CAD technology in one of three ways: as physical capital, as supporting or extending

To understand the

human

or as enabling

capital,

received from

role

improvements in social capital. Further, the value depend directly on how managers view the

the technology will

Managers who see the systems as physical capital (i.e. electronic drafting some benefit; managers who view the systems as enabling improvements in social capital will receive the greatest benefit from the technology. The characteristics of each of the three views of CAD technology will be technology.

boards) will receive

discussed, as well as the barriers that prevent companies from realizing the full benefit of

CAD

technology.

Introducrion on reducing product

In recent years, industry has focused a considerable effort

development

Many

times..

Design (CAD) systems

have

made

may

believe that the appropriate use of

CAD

systems- expenditures have reached SI 00

million for a single company's hardware and software.

hardware and software was over 17

billion dollars in

The market

1987 and

is

many

for

CAD/CAM

expected to grow

to

[28].

There has been some debate, however, over the benefits of

While

Many companies

aid significantly in achieving this goal.

large expenditures on

39 bilUon by 1991

Computer-Aided

organizations have

of these organizations

made

do not believe

large investments in

their

money was

CAD

CAD

systems

technology,

[13].

some

well spent. These

organizations are not seeing the benefits they expected from their systems. In the following sections, the results of an investigation into the uses of

systems

at

CAD

twelve manufacturing companies are reported. The goals of the research

are to understand

how

the systems are used,

what

difficulties

implementing the systems, and what benefits resulted. introduction to

CAD

literature relating to

systems

is

occurred

in

In the next section,

an

presented, followed by a brief review of the current

Computer-Aided Design.

CAD Systems Introduction

CAD the design

computer

systems are defined in

this

paper

to

be those computer tools that support

and design engineering processes. This tools

definition thus includes

normally classified under Computer-Aided Design, Computer-

Aided Drafting, and Computer-Aided Engineering (CAE). The greatest use tools

is

in the

support of mechanical design and engineering

[20];

it is

of these

that area of

application that will be addressed in the present paper. features

and functions

CAD

found

of such software can be

systems can potentially lead to

organizations. For example,

CAD

More

inforniation about the

in [4], [20].

many important

benefits for

systems can potentially reduce the length of the

product development cycle and improve relationships with both vendors and customers.

The

have helped

to

literature provides

many

descriptions of

reduce the product development time

shorter design cycle allows companies to respond challenges, incorporate

newer technology

CAD

applications that

([3],[5],[6],[14],[23],[25],[27]).

more quickly

into products,

A

competitive

to

and charge higher

prices for

unique features.

CAD its

systems can also help improve a company's links with

customers

For example, one airframe manufacturer provides major

[7], [11].

customers with a

CAD

terminal.

personnel can access the

CAD

If

a

design

the manufacturer's support personnel

make comments on In either case,

there

is

less

a

CAD

file

problem occurs file

and

either (1)

communicate by phone with

(who can access an

and send

communication between

the

file

identical

CAD

and

its

customers

ambiguity in the information communicated, and there

limited.

CAD

customer

is

(2)

is

is

much

faster,

less

sites.

systems, our understanding of the

In the next section, a review of the literature

systems in organizations

or

file)

electronically to the manufacturer.

the manufacturer

Yet despite the potential benefits of is

maintenance

in the field,

travel required of the manufacturer's support personnel to

systems

vendors and

its

on the use of

CAD

presented.

Research on the Impact of

CAD

The academic and trade

Systems

literature provides little

organizational actions are necessary to utilize

CAD

guidance on what

systems

for

maximum

benefit.

The studies

"competition" studies, social

in the literature fall into three categories:

impact studies, and case studies. In the "competition" category are studies

which

test the

performance of

CAD

systems against drafting boards. Such studies show productivity gains from 25%

350%, depending on the complexity and repetitiveness of the task type of task.

Many managers

interviewed for

own

gains

do not always occur

some

finding for enrichment of jobs

in their

Some

skilling" [10].

results

were

changes in

studies even

[1],

study report, however, that such

systems have produced mixed

and others finding

show both

Some

that

CAD

companies report

results,

leads to "de-

These mixed

effects occurring [18], [26].

also seen in field interviews- different

jobs.

and on the

[19],

companies.

CAD

Studies of the social impact of

this

to

different

reported that the work had become more repetitive, others

stated the opposite. In the third category of research, case study research,

companies report the

productivity gains from implementing a certain system or application.

Swerling the

IBM

[24] reports that the

For example,

use of computer tools cut the development costs for

3081 computer by 65%. Bull

[5]

CAD/CAM

reported that

improved

productivity for product development by 150%. Chrysler estimates that computer tools will cut the

Kodak

development cycle

[12] linked

for

new

cars

from

five years to four or less [14].

product designers and tool designers through a

common CAD

system and were able to develop the "Fling 35" camera from project approval in 38 weeks. They estimated that

this

CAD

start to

shipping

system helped them reduce

development costs by 25%. Unfortunately, with few exceptions, this third category of research provides

managers

little

organizations.

insight into

The studies

characteristics of the

new

how

to

in this

achieve similar gains in their

own

stream of research focus largely on the specific

technology, and ignore the other technological and

organizarional changes that must be

advantage. With few exceptions

made

to utilize the

(e.g. [15], [23], [26]),

it is

technology

not clear

to full

how

the results

achieved in these studies could be repeated in other organizations. It is

important to note that the large gains reported in the case study literature

are hardly guaranteed-

has hurt productivity is

less likely that the

some managers

CAD

The reason

CAD

CAD

systems

systems are mixed,

it

negative impacts would ever be reported in the literature.

Thus we cannot count on the experiences with

the productivity gains of

If

(cf. [13]).

believe that the introduction of

literature to accurately reflect the average

companv's

systems.

convergence

for the lack of

in the social

managers' disagreement with case study results

is

that

impact studies and

CAD

systems do not

necessarily cause any changes to occur to the structure or processes of an

organization- they only enable changes. The eventual use of a

much

orgaruzational environments as

it is

complex technology, and

Different Perspectives on the

developed

of physical,

in this section will

Physical,

human, and

development process.

A

is

as

Thus

different

systems are a

their application in organizations tends to reflect the

characteristics of the organization as

The concepts

CAD

system

and

of the features of the system.

organizations can (and do) use the systems quite differently.

field.

CAD

a result of managerial decisions, individual predispositions,

much

as the features of the technology

[2], [IS].

CAD Investment

human and

social capital that are defined

and

be used to analyze the observational data from the

social capital can be seen as resources in the

good manager

will

develop and use each

to its

product

maximum

advantage. Physical Capital comprises the machines and equipment that are used to

add value

to a

product, or allow a product to be developed

more

efficiently

(i.e.

more

quickly or less expensively). The cost and value of this type of capital are relatively

well understood by managers. of a company's workers

development, or

Human

that allow

Capital comprises the skills and knowledge

them

add value

to

develop a product more

to

to a

to

The

is

done with the

company upon

to the

is

between individuals

development or develop

implicit

assumption

a

Social Capital that allow

product more

[9].

them

to

classes, or

employee

is

degree

worth

Social capital resides in the

add value

efficiently.

property of the individuals in an organization-

it is

As with physical and human

individuals.

that the

returning from such as experience.

third type of resource

relationships

among

they cannot quantify the

months, or even years so that they can attend seminars,

programs. This

its

if

be received. For example, managers and companies will release employees

for weeks,

more

its

Managers are usually

efficiently.

willing to pay the cost of developing this capital, even

value

product during

to a

Social capital

product during is

not a

a property of the relations

capital, social capital

completely fungible- the development of a certain type of social capital

is

not

may

be

productive for certain tasks, but have no effect or be harmful for others. Managers often

do understand

that the ability' of their

accomplish goals has

a great deal of value,

employees

and

that

to

work

together to

developing social capital can

return large benefits.

Many

creating liaison roles,

or adopting a matrix structure are undertaken to improve

organizational actions such as forming ad hoc teams,

social capital.

Research Method To understand how organizations were conducted produced jet

a

at

are using

technology, field interviews

twelve manufacturing companies. The twelve companies

wide range

of different products, including college rings, plastic bottles,

engines, airframes, copiers, and automobiles.

understand:

CAD

The goal

of the interviews

was

to

of the design engineering process,

•

The nature

•

The coordination demands

•

The

•

The changes

features

and

of the design engineering process,

capabilities of

CAD

occurred since the introduction of •

The nature

systems,

and structure

in the process

of the companies'

CAD

of the organization that have

technology,

management and

their attitudes

toward

CAD

systems, and •

The

potential future changes that are enabled

by the systems.

Interviews were conducted with a broad cross section of roles, including

design engineers, managers,

CAD

support personnel, and others.

design engineers, 32 managers, and 22 the 12 companies.

CAD

A

total of

46

support personnel were interviewed

In addition, 39 individuals

in

from other groups which assisted the

design engineer in his or her work (such as analysis or manufacturability groups)

were also interviewed. An average of two days was spent

The goal

of the interviews

and the role computer

was

tools play in

it.

to

in

each company.

understand the design engineering process

Investigating the use oi computer tools

throughout the product development process was outside the scope of the research; it

was decided It

was

of the ten

to focus solely

on the design engineering phase of the process.

also decided that the research should focus

on the design engineering

companies developing complex products. Significant differences were

noted between simple and complex product development processes.

Thus the

conclusions reached in this paper will not necessarily apply to the design

engineering of

all

products.

The Design Engineering Process

Many

authors have characterized the product development process as passing

through a number of stages. Myers and Marquis

[21], for

example, describe

five

stages:

and

problem solving, solution, and

recognition, idea formulation,

diffusion.

Roberts and Frohman

utilization

by designating Myers and

[22] call for six

Marquis' "solution" "prototype solution" and adding "commercial development" as

an additional, and

we might

add, a very important phase. Clark and Fujimoto

return to five phases, based on the automobile development process:

[8]

concept

generation, product planning, design engineering, process engineering, and

production.

Building on these earlier formulations,

we

will present another

characterization of the product development tailored to the current research.

goal the

is

to build a general

many

different

model

of product

In the Recognition phase, the

phase, a design specification for a

that a prototype

built.

is

identifies a

is

design

new

translated into a set of detailed drawings so

In the Prototype

Refinement phase, defects are to the

prototype.

After the

decided upon, the Process Engineering phase begins. In

design specifications are used to create a process design,

which may include flow

charts, plant layouts, tool

phase has been completed Utilization

is

for a

developed. In the Design

removed and additional improvements may be made

this phase, the detailed

need

technology. In the Idea Formulation

new product

this specification

product can be

final version of the

to

development process can be described by

company

new

product or a potential application of a

Engineering phase,

development which corresponds well

complex product development processes studied.

In the products studied, the product six phases.

The

(as

and die designs,

judged by the success of a

pilot

etc.

When

this

production run), the

and Diffusion phase begins.

This research focuses on the Design Engineering phase of the product

development process. In the next are presented.

section, the observations

from these interviews

The

Field Interviews

The Design Engineer's Tob Engineers in the design engineering phase of product development are often

organized functionally around either parts of the product or types of analysis

Design engineers

[17]).

responsible for

may

be assigned a part or group of parts and are then

completing the design of those parts (and are often responsible for

the parts during the later phases of product develpment). typical

(cf.

work process

(for the

The organization

of a

companies studied) can best be described by an example.

The design engineers responsible

for the engineering of a gas turbine

engine

are usually organized around the different parts of the engine- the compressors

(which compress and heat

air),

the turbines (which drive the compressors), the

burners (which mix compressed bearings (on which

systems

all

with fuel and ignite the mixture), the shaft and

air

rotating parts turn), the static structures,

(for circulating air, fuel

and

oil

around the engine). The engineer

responsible for the engineering of a turbine blade

Turbine group, which

is

responsible for

and the overall

all

would

report to the

manager

parts in that area of the engine.

of a

This

engineer would work with the engineers responsible for the parts adjacent to

his:

engineers in the Static Structures group, the Shaft and Bearings group, the Systems

group, and the group responsible for the next and previous stages in the engine (possibly a

Compressor group and the Burner group).

In addition, this engineer

may

be required

to

work with many

other groups.

For example, for the design of a turbine blade, the design engineer must work with the

Aerodynamics group, who provide

Aeromechanics group,

who

test the

Stress

and

who

test for

temperature gradients

Life Analysis groups,

airfoil

shapes

to the engineer; the

vibration properties; the Heat Transfer group, to

who

ensure that the blade

is

cooled properly; the

check the stresses on and wear of the blades

and predict how often they would need

to

be replaced in the

field;

the Drafting

who add

group,

dimensional information and additional views

to the

design

to

prepare the design information for manufacturing; one or more testing groups,

who

are responsible for completing the necessary engine certification or qualification tests;

which

a performance group,

specifications are met;

and

a

output of the engine

tests the

Manufacturing representative,

ensure that

to

who

ensures that the

part can be built for a reasonable cost in a reasonable period of time. Other groups,

such as a materials research laboratory,

The engineer responsible as well as

work within

his

own

may

occasionally be involved.

must balance the demands

for a part

constraints.

The Aerodynamics group

airfoils for optimal airflow characteristics, while the

thicker, stiffer blades to

and Aeromechanics groups'

goals.

may

prefers thin

Aeromechanics group prefers

reduce vibration. The Heat Transfer group

cooling channels within the blade, which

of each group,

conflict

may

require

with both the Aerodynamics

Against each of these groups' demands must be

balanced the cost and weight of each design alternative. Finally, a design which

works well may not be durable, maintainable, have

to

and thus may

or manufacturable,

be redesigned, necessitating changes undesirable to any or

The

overall job of the design engineer

requirements.

Unfortunately, this

is

often

is

when asked

groups.

one of balancing conflicting

done by incorporating

perspectives sequentially and iteratively converging on a solution the design engineers,

all

to describe their job,

different (cf. [6]).

Many

manager." They describe their job as one of coordinating a group of people carry out the bulk of the design

time

is

and

analysis work.

of

used the term "project

Most

who

of the design engineers'

spent coordinating efforts between the different groups.

Design engineers also perform design and analysis work on analysis performed

by the engineers was largely described

analyses to understand the feasibility of

new

as "quick

their

and

own. The dirty"-

ideas, or to check the accuracy of results

generated by other analysis groups. The engineers do perform some design work.

10

which involves generating new design

This

possibilities.

(in

most companies)

is

the

smallest part of the design engineers' work.

CAD

Systems

CAD

technology has been applied in

many

different

ways

many

engineering work, and design engineering work was changed in

ways with different

the introduction of

companies was due

engineered and to variations similar systems

Two

CAD

different

systems. The divergence in the experience of

in part to the different types of products being in the capabilities of different

were sometimes applied

different groups in the

design

to

to similar tasks in

same company doing

CAD

systems. Yet

very different ways.

similar tasks sometimes have

CAD

One

significantly different experiences with the

same

variance, the design engineers believed,

the variance in managerial attitudes.

Managers structure

the

work

deadlines for engineers.

work to

is

is

for design engineers.

They have

They

a large voice in

carried out. Managers' attitudes about

system.

allocate resources to

determining

how CAD

cause of this

how

and

set

engineering

systems should be applied

engineering work varied widely.

CAD

Systems

as Electronic Drafting

Some managers saw understandable, as

CAD

Boards

systems as electronic drafting boards. This

many managers gained

systems were developed and

may

their engineering experience before

not have had the time to learn the

technology. Managers of this type often view

CAD

additional (and, to them, mysterious) features.

performance improving on some attitude similar to that of

as a drafting

They see

tasks, but declining

on

For

some

CAD

new

board with some

their subordinates'

others.

Many

one manager interviewed: they view the

drafting board with a "rr,agic button."

is

CAD

tasks, the productivity

adopt an

system

as a

advantages

11

CAD

of the

system were undeniable. The production of a slightly different version

of a previously designed product

But

this

complex his

way

CAD

was accomplished by

magic button did not work For tasks such as

parts.

(which often

means on

this, this

the

CAD

system very quickly.

such as the design of

for other tasks,

manager

new and

will require that the task be

done

the drafting board).

Svstems as an Engineering Support Tool Other managers believed

different than designing

on

a drafting

board, especially

Such managers would require

three dimensions.

CAD

on a

that designing

if

system the

is

CAD

a process very

design

is

done

in

that all design engineering be

done

in three dimensions; they stated that, while designing in three

more

difficult

and more time-consuming process,

it

dimensions

is

a

provides significant benefits.

Designing in three dimensions requires greater mental involvement with the part to be

designed-

completely.

it

requires that the entire part be considered simultaneously and

Design

in

two dimensions allows some cheating- some important

design details can be ignored and

left for

a

downstream process

to

determine.

For example, designing the shape of a turbine blade in two dimensions

done by specifying the cross-sectional dimensions

of the blade at various points

along the blade. During construction of a prototype, a blade

connecting the cross sections with straight decide

how

a process in

the exact

more

to

fill

lines.

which

dimensions

on

errors can be introduced.

is

When

produced by will then

that (1) the time to (2)

the

produce the

downstream processes

prototypes) are shortened.

designing in three dimensions,

specified,

the part of the design engineer.

-lengthened and

is

The design engineer

or smooth this prototype to produce the final surface dimensions-

shape of the turbine blade must be

effort

is

The

a

good deal

result of designing in three

first set

(e.g.

which requires

of engineering

the production

drawings

and

is

testing of

12

Some managers for a better simulation

also stated that the analysis features of the systems allowed

and

testing of the design before

any hardware was

built.

For

example, an engineer in one automobile company built a model of half of an axle

and suspension system. He was able

rough road. The simulation

travelling over a

results

performance of an actual axle corresponded well

The simulation provided the engineer information about the

results.

axle

to simulate the

and suspension

production of a

months

to

new

that

were

likely to

to

CAD

two days. The

areas of the

In the field, the failure of a part,

redesigned part, and retest of the part would take

complete. The use of a

completed in one

fail.

to test track

at least six

simulation allowed the same cycle to be

result

understanding of the design, and a better

was first

the complexity of the analysis, however, the

that the design engineer

had

a better

prototype was completed. Because of

first

prototype was completed behind

schedule.

A

similar experience

was reported

in a gas turbine

certify (as this

can occur during

flight).

The

simulated turbine blade was used to respect.

intersection of a simulated bird with a test the

performance of the engine

Again, the results of this simulation

first

prototype.

Systems and Communication

CAD Some

in this

improved the engineers'

understanding of the design and the quality of the

CAD

engine manufacturer. To

an engine for commercial use, the engine must survive the ingestion of birds

systems

engineers,

in

when

many companies were used

to

improve communication.

trying to explain a design concept to others or resolve a

design conflict with others, will often coordinate with others in front of a terminal.

The

rich representation of the design available

on the

helps ground conversations and minimizes misunderstandings.

help create a

common

CAD

CAD

terminal

CAD

systems can

language between groups with different backgrounds and

13

In fact, design engineers will often design in three dimensions, even

jargon.

designs are

still

on paper

transferred officially

if

Design engineers

to other groups.

report that a face-to-face conversation with a three-dimensional model as an aid

may be

the only

way

Another use of

adequately explain the design to others.

to

CAD

airframe manufacturer.

CAD

which a

When

the

company

This

terminal display

created a

"CAD

was projected onto

CAD

projection-TV screen.

a large

design the "noise,"

way

drawing of the part

in question

all

parties involved

was changed,

by the engineer on the terminal. Thus,

or simplified

in

the change, with the engineer in charge of that part using

CAD

The

terminal.

to,

a large

Design Review Room,"

engineering changes to a part were requested or required,

would meet and review

added

systems as a communication aid was found in

they needed to see

One

it.

person's "detail"

and with the CAD-based design representation

all

is

all

rotated,

groups saw the

another person's

groups could see the

design in the manner they preferred. Engineers will also use the systems to coordinate with others by accessing others' design

between

work

Many

directly.

Engineers

parts.

systems and check the coordination through

fit

of those parts with their

CAD

systems

Purchasing organization chooses a

geometry and

design errors are simple gaps or interferences

some companies could

in

to read'

any releases or

between these deparments

thereby

change that occurred

group responsible

was

is

in

call

and purchases them

tell

anyone

made more

CAD

library

by

a

CAD

CAD

The

in bulk.

The

which

which fasteners are preferable in Purchasing.

The coordination

efficient.

one surveyed organization was the removal of the

for integrating the different parts of a large project.

replaced, in effect,

their

own. Another example of

characteristics of these parts are placed in a

without having

on

the use of standard parts libraries.

is

set of fasteners

engineers can access. Thus engineers can easily

A

access other parts

file

This group

containing the designs for the different parts of

u

The

the product. to

central

CAD

file

was

ensure that the parts they designed

with the

can be responsible for understanding the parts

around

A

by

accessible fit

fit

and was used by

all

engineers

Each engineer

of that engineer's part with the other

and for resolving any problems that occur.

it,

example was found

similar

conceptual design of a

in

new automobile

is

done through

When model

is

digitized

and

information

this

is

the creation of a clay model.

new model

is

sent to the Packaging

The Packaging group determines

within the automobile.

The

an automobile manufacturer.

the conceptual design of the exterior of the

other groups).

all

rest of the project.

complete, the clay

group

the placement of

(as well as

components

all

"Envelopes" for each area of the car are created, which

define the outlines of the space for the passenger compartment, luggage

compartment, engine, transmission, drive components,

The Packaging group models of

all

space

is

where

components, and

it

must place

now

its

it

takes

much

this

CAD

file to all

groups, defining the

model, each group

and with which group

longer to build the

major auto components. The the

parts

CAD

transfers a

it

component envelopes

for

result,

is

as

large

a

more complete

more

and all

specification of

under the hood leads

to less conflict

fewer misunderstandings occur. This in turn has led

relationships between groups

if

dowmstream processes. Managers downstream report

that this better definition of the space allocation

between groups,

is

three-dimensional model of

full

however,

now knows

must negotiate

needed. The productivity "impact" on the Packaging group

negative-

CAD

recently started building full three-dimensional

envelopes exactly for the groups. With exactly

suspension, gas tank, electrical

train,

etc.

and greater productivity. Furthermore,

to better

this

automobile manufacturer believes that the overall development time will be cut significantly.

15

Concurrent Design

Although concurrent design was not intended

managers interviewed

in

as an interview topic,

every company mentioned some effort to implement

concurrent design practices. The level of effort

is

quite different in different

companies, however. One airframe manufacturer has radically changed the organizational structure, physical location, and design process to insure that

groups are involved

companies, while endorsing concurrent design practices, did

encourage engineers to meet

companies had

tried

more

implementing

little

the meetings

more

that

Four

often with engineers in other groups.

a policy that required the design engineer to

meet regularly with representatives from other groups, but these

dropped when

all

and design engineering process. Other

in the design

were found

to

efforts

were

be unproductive.

Discussion Managers

in

every company surveyed exerted a large influence over the

design engineers and their use of of the capabilities

how

and

limitations of

effectively the systems

physical,

toward

human, and

systems.

CAD

were used

Managers' attitudes and knowledge

systems were a crucial determinant of

(cf. [2], [16], [26]).

social capital will

In this section the concepts of

be used to categorize managers' attitudes

CAD systems.

Managers views corresponding

CAD

CAD

of

to the three

systems as physical

and some

CAD

as enabling

systems can be classified into three categories

types of capital discussed earlier.

capital,

some

improvements

as supporting

Some managers saw

and extending human

capital,

in social capital.

Fhysic3l Capital

Some managers saw CAD systems

as physical capital, as electronic drafting

boards. Managers in this category (such as the manager

who saw

the

CAD

system as

16

a drafting

system.

board with a "magic button") did realize

The engineers

productivity gains from the

deprtments would openly express frustration

that

could be done withthe systems.

much more

Human

in these

son-ie

Capital

Some managers understood

that

CAD

systems could provide the design

engineer a better understanding of the design; they saw or extending

human

capital.

Managers

in this

CAD

systems as supporting

category believed that

CAD

systems

allow the design engineer to understand the geometry and characteristics of the design more

The detailed representation

fully.

of the design, coupled with

sophisticated rendering capabilities, allow the design engineer to understand the

design in more

detail.

Design engineers working

at a

CAD

terminal reach a

"resonance" with the design- an ability to understand the design in great detail- that is

not as easy to achieve with a drafting board. With

CAD

systems the design

engineer has in front of him a tool that allows him to work with the design as

when

appear

it is

produced. Engineers report that the tool

that engineers are able to concentrate

The transparency

Managers complete a

full

and

on the design and forget about the

in this category

medium

allowed

three-dimensional model

improve the engineers' others).

less to the

ability to

will

in effect "disappears,"

of the tool enables the design engineer to devote

the design process,

it

more

tool itself.

attention to

of design.

their engineers the time necessary to

CAD

model, as they realized

understand the design (and

These managers would also allow the time necessary

to to

it

would

communicate

it

to

perform detailed

analyses of the designs, as they gave the design engineers a better understanding oi the characteristics of the design.

Social Capital

The

third category of

in social capital.

managers saw

The managers

m

CAD

systems as enabling improvements

the previous group, while understanding the

17

CAD

capabilities of ability of

CAD

systems as individual support

systems

to

tools,

improve communication between individuals

groups. These managers took advantage of the ability of

"common language" between

communicated design information around

a central

Of

CAD

file

viewed

improvements

CAD systems

in the copier

and

human

and 7 viewed

capital,

This rating

in social capital.

is

as physical capital, 6

unambiguously

company

Managers were not asked

subordinates. In every

is

viewed

CAD

CAD

or the

was always

models, checking the

fit

at least

of the

systems as enabling

the subjective

judgement

an

of different applications of

this

had

companies, but were supported by management

8:

Factors Affecting the

There are

many

systems are used and

make

management

CAD

These enablers

CAD

with the in

some

Systems

systems for various fall

model

in others.

how CAD

which uses the systems can be applied. These

possible the use of

referred to as enablers.

Use of

to fight

the

to others

organizational policies and actions that affect

to

CAD

one engineer building three-dimensional

model with other engineers, analyzing

Engineers such as

aid.

of the

their

systems by the managers'

with whatever tools were available, and explaining the design as

systems as

to classify themselves.

company, there was evidence

systems. There

CAD model

CAD

based upon the interviews with the managers and

subordinates, as well as the actual use of

actions

CAD

the automobile Packaging group.

supporting or extending

Section

to act as a

the 29 managers interviewed in the ten complex product development

processes, 16

authors,

systems

company, enabling improvements

a

such as the removal of the integrating group

CAD

in different

and (where possible) used

different specialties

design review rooms. They understood that

improved layout from

did not understand the

activities,

policies

and

and are thus

into three general categories:

basic

18

enablers,

which allow the use of

enahlers,

which allow

coordination enahlers,

CAD

systems as physical capital;

and extend human

the systems to support

which allow improvements

human support

capital;

and

in social capital.

Basic Enablers

Good very

More

how

Training:

little

Many

to teach

training classes (including those offered

an engineer

how

often, these classes provide

an introduction

by most vendors) do

technology to the tasks to features,

but

little

those features should be used. By the time the user has learned

the basic features to his or her forgotten.

The

best

CAD

own

job, the

and complete

to class,

Good Support A good support group

to tailor the

accessible

to

guidance on

how

to

apply

features have been

that task

by the end

keep the system operational, and will respond

system

hand.

company-specific

and must respond quickly

S low Hardware/Inefficient Software

tasks.

A

to users' requests

good support group must be

to requests.

:

hardware and software. Engineering involvement with the work.

of the class.

will provide assistance to users in learning

:

features, will

more advanced

at

training classes require that the engineer bring a design

problem from the workplace

new

CAD

apply

to

Many is

engineers are working on outdated

a process

which requires great mental

Having concentration broken by slow response time

can drastically affect productivity. With the cost of machine power falling rapidly

and the

cost of labor increasing,

upgrade difficult.

their systems.

it is

Yet without

understandable this,

Unfortunately, response time

why many companies

wait to

design in three dimensions can be too

is

not dependent on machine hardware

alone- poor response time can be caused by poorly designed software as well.

19

Ease of Use and Usefulness

:

A

system that

overly con-iplex in

is

its

that lacks functionality will not allow organizations to gain the full

CAD

execution or one

advantage of

technology.

Human Su pport

Enablers

Managerial Understanding of capabilities

and limitations

CAD

Systems

:

managers do not understand the

If

of their subordinates' systems, they cannot adequately

judge their subordinates' behavior. The drafting board provided the manager with instant feedback

on subordinates' progress; measuring work progress with

systems requires that the manager understand

CAD

model. This

is

much

who understand CAD proposed

new

curve costs are

easier

CAD

if

when

progress has been

capabilities are

CAD

made on

a

known. Further, managers

technology can more accurately gauge the benefits of a

application,

and can

better guess

whether the financial and learning

justified.

Enforcing Three-dimensional Usage

:

Engineers sometimes

resist

designing

in three

dimensions. The design takes longer to complete and must be thought through

more completely; much

greater concentration

is

required in the process.

Yet

designing in three-dimensions allows other activities to occur: •

Designing in three-dimensions with surfaces or solids provides a

A

manufacturability check. surface or solid models,

much

it is

rule of

thumb

is:

"if it is

difficult to

design with

impossible to manufacture." In addition,

easier for an experienced

manufacturing engineer

to

it is

check a three-

dimensional model for manufacturability. •

When

designing in three-dimensions there

engineers can

work from

the

is

less

duplication of effort-

same model. When designing

dimensions, the analysis groups must construct their

own

in

all

two

three-dimensional

20

models, which

want

also

may

to see the

be different from one another. The different groups

model from

can

all

a different angles, or see different

Or\ly with three-dimensional representation

information about the model.

•

may

groups work from the same model.

With three-dimensional design, to others, as the design

there

is

a greater ability to explain the design

can be rotated and

(if

surfaces or solids are used) the

design can be shaded and hidden lines removed.

Coordinat ion Enablers Required Use of requirement for created strict

on

CAD One

CAD

:

use,

CAD systems.

major step that

i.e.

many companies never make

the requirement that

CAD will impose

information from the

Moving

a cost

non-CAD

the Official Design

on those

CAD

is

the

products be

systems, coupled with

systems. Those engineers

who do and who need

who

to access design

user.

Document onto

CAD When CAD :

generate a paper document which becomes the

make

CAD

new

parts for

Often, the learning curve for

deadline pressures, will inhibit the use of

do not use

all

official

models are used

to

design document, the urge to

last-minute changes to the paper document only can be quite strong

take ten minutes to erase and change the paper, while accessing the

file

(it

may

on CAD,

changing the model and generating a new drawing can take hours). Yet coordination through the

CAD

data

files is

much more

difficult

if all

design

information cannot be accessed, or the design information on the system

is

not

current.

One Model

:

Different groups

may need

to see the

design in different ways.

Returning to the turbine blade example, an Aerodynamics group

is

concerned with

21

airflow lines, while an Aeromechanics group

A

surfaces.

strategy

and more prone

less efficient

use, or

the initial

if

which requires

model

is

to errors

Adding

Intelligence to the Design

amount

information to those effective.

CAD

File

file

transfer in

who must

quickly.

if

a single

If

model

all to

is

own model

translated for

is

much

all to

access.

there exists an organizational

norm

that the

access

:

A

file

it,

will provide a richer source of

and thus make coordination through

naming convention

CAD

for design data files can aid

design data by engineers, and thus enables coordination by

some

instances.

Standardized Use of Levels coordination.

:

CAD

Naming Conventions

in the location of the

CAD

than

its

of information possible about the design should be placed in the

with the geometry, then the

more

concerned with cross-sectional

complete enough for

greatest file

is

each group construct

that

Naming

:

Naming

CAD

systems

for

levels helps other engineers locate the parts of interest

Further, standards for

geometric information

of levels can aid in the use of

is

where design data

is

placed and where non-

placed can aid in the understanding of another engineer's

work.

Network Transparency The :

current

work

area

is

ability to easily access others'

important to using

Incompatibility of systems and data

communication networks can

CAD

fUes.

all

CAD

files,

work and bring

it

into the

systems for coordination.

or technical problems with

affect the engineers' ability to

work with

others'

22

Presence of a

CAD

implementation of the presence of a

Design Review

CAD

CAD

:

characteristic of the

technology that allows improvements

design review room- a room with a

to a projection-screen television.

coordinate work

Room Another

Such rooms are helpful

in

CAD

using

in

coordination

is

terminal connected

CAD

to

across groups (as discussed earlier).

Conclusions There are four specific observations that are important

some

there are

significant production-related benefits of

CAD

to

emphasize.

First,

Even

systems.

if

CAD

systems are used solely as electronic drafting boards, some productivity gains will be achieved.

Second,

common

CAD

systems,

language or

set of references.

and interdependent groups

The combination

when used

as

This

to conversations, create a

common

language allows differentiated

communicate about design-related

to effectively

of a face-to-face meeting

representation of the design lead to a

an aid

and the

medium

of

availability of a rich

communication

that

and is

issues. flexible

both

unique and powerful. Third, while the

way

CAD

systems

engineering work

is

done,

The manager who believed the

CAD

be directly responsible for some changes

many changes

initial sales

work

is

CAD

systems can lead

to large

it

CAD

CAD

gateway innovation- an innovation

CAD

that

is

in productivity, but

to

only

CAD

allows them to be used as a

important for the other innovations

systems should be evaluated for their

design changes, and not expected

systems.

takes for engineers to produce

improvements

medium

in

systems was misled.

reorganized to take advantage of the features of the systems.

systems' effectiveness as a communication

allows.

are only enabled by

pitches for

systems do not necessarily decrease the time

drawings. the

may

ability' to

enable productive

automatically cause changes.

it

if

23

Finally, the

what appear

to

most productive changes enabled by

be productivity losses

improve coordination result in

More

more

w^ork

is

The use

level.

earlier,

and the

productivity gains downstream It is

CAD

of

and more

result

that

is

may

(e.g. in

Many companies

other group

to

may

being resolved early.

conflicts

it

take longer to complete

some

to occur, as the

the prototype refinement phase) can be

may

lead to significant

downstream

are experimenting with or have

gains.

implemented concurrent

design methods. Concurrent design practices force the design engineer other groups

systems

imjxjrtant that these apparent productivity "losses" be recognized as

an "investment," as they

all

entail

in the early stages of the design engineering process

issues being raised early

done

group

may

systems

Schedules should be adjusted to allow these changes

initial tasks.

significant.

at the

CAD

when making

to

work with

design decisions. Rather than working with each

sequentially and iteratively converging on a solution, a concurrent

design process will require the design engineer to involve

design decisions. The communication demands are thus

all

other groups in

much

greater.

design has some dear benefits: a wider involvement in the design engineers' understanding of other groups' specialties and

(2)

(1)

all

Concurrent

increases

changes engineers'

relationships with other groups. Instead of only seeing a small part of the process,

individuals from different groups are invited into the central flow of the product

development process. This makes the tense,

and

conflicts that inevitably occur

much

less

easier to resolve.

CAD

systems have the potential

to

within the product development process.

improve the If

CAD

design information, concurrent design meetings the entire process

may

be more

design information enabled by inefficient to

be worthwhile.

effective.

CAD

ability to coordinate

systems are used

to

may become more

Without the

effective

systems, concurrent design

work

communicate

productive, and

communication of

may

be too

24

CAD

systems will not cause any major changes by themselves, but

changes that can lead to significant productivity gains.

CAD

systems

may

systems are used limitations of if

is

CAD

they are to see a

not be sufficient to enable

important.

may

enable

Further, the simple use of

some changes-

way

the

Managers must understand the

in

which the

capabilities

and

systems, as well as the nature of the changes the systems enable, full

return on their

CAD

systems investment.

25

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Date Due

W^

SEP 10 JAN.

OCT

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