pro and con, that software reuse is delivering. ... five being the best possible rating. 1. .... in-house. Based on this experience delivered software is written in C by ...
SOFTWARE
REUSE: IS IT DELIVERING?
ModeratoE
William
B. Frakes, SPC
Panelists:
Ted J. Biggerstaff, MCC Ruben Prieto-Diaz, SPC Introduction
Kazuo
Matsumura,
Wilhelm
Schaefer, U. Dortmund
5. The experimental many field
William B. Frakes Software Productivity Consortium Herndon, VA 22070
Toshiba
evidence
has been validated
If our panel
members
feel that reuse is delivering,
they will tell us how large the quality
and productivity
The purpose of this panel is to examine the evidence,
increases are, what level of reuse produced
pro and con, that software
what factors
account
Our
respondents
cide whether
software
reuse is delivering.
reuse is delivering
agree on what reuse is, and on criteria its success. Ted Biggerstaff it has promised.
To deliver,
and repeatable ductivity
infield
increases in software settings.
tools and methods itself,
Other
support
quality
of the primary
goal of increased
reuse by
quality
Panel members will use the following reuse is delivering.
After
in
five being the best possible
listening
additive
and
to a series of speakers, each promising
productivity
suspiciously
is no evidence
increases in software
that
quality
reuse
is producing
soon our inter-
development
will
reusability
Unfortunately,
Hyperbole
and productivity.
bullet
increases in software
3. There
quality
is quasi-experimental
is producing
increases
and quality.
and productivity,
evidence
in software
hyperboles
software
than software
be applied
of magnitude
be so effi-
a profit.”
As in this
often strain cre-
reusability reusability
reusability universally
hyperbole reality.
is not a silver and casually to
increases
in productivity
On the other hand, it is a technology
in the hands of the skilled can be of significant to software development and maintenance.
that reuse quality
activities
notwithstanding,
that en
reap orders 2. There is aneedotal evidence that reuse is producing
summing
“If this keeps up, pretty
dulity.
rating.
were
one wag was heard
to comment,
story, software
with
that
nal software
is more seductive 1. There
increases
close to 100 percent,
cient that they will start returning
scale to evaluate
The wale is ordinal,
in their parts of the world.
Ted J. Bigger.staff MCC
productivity.
whether
is delivetig
and pro-
results
from
from the U.S. will discuss how reuse, as
successes, like better
as intermediate
Schaefer
from Japan, and Ruben
Software Reusability Promise: Hyperbole and Reality
in verifiable
for reuse, and increased
are only interesting
defined,
means.
Wilhelm
Kazuo Matsumura
Prieto-Diaz
what reuse is and what
reuse must result
three
Germany,
for the pur-
I will define what “delivering”
increased
them, and
for the reuse.
we must
for measuring
will define,
poses of the panel discussion,
To de-
in
studies.
There
and
productivity.
are several major reuse hypedmles
that value
that refleet
some measure of truth but unfortunately
overstate
profit of reuse or understate
qualifications
the required
the
and constraints. 4. There
is experimental
producing
increases
evidence in
software
that
reuse
quality
is 1. The
and
factor
productivity.
52
CH2982-7/91/0000/0052$01
.00 @ 1991 IEEE
reuse
technolo~
“is
the
most
important
to success.” This is an aspect of the silver
bullet attitude
and is typified
by statements
I choose Ada, or Object-Oriented or an application
generator
like “If
standards
programming,
ability
then all other factors
to enhance
and careful
components
component
adaptation
interconnect-
of the harvested
to the interconnection
standards.
are second and third order terms in the equation that defines the expected improvement. assured.”
This is seldom
the technology application
Success is
completely
true. While
can have very high impact (as with
generators
for
example),
the application
domain,
is understood,
change within
rate
the domain,
of the development
and so forth.
Yes, the technology
it is not always primary
attitude
Now let’s ask the opposite required
but
factors that foster ●
everywhere
Narrow
stood application technologies
or appli-
with the same expectation reality
is that narrow,
domains
with
and standardized
the most likely
to provide
well
slowly
under-
changing
architectures
a context
●
of high
successful
domains.
where
defined
merical computation, extent,
product
reuse
lines,
ished in these environments. understood
domains
allow
the use
and increase the amount that
of
can be constructed
Well understood
domains/architectures.
Without
a good model of the application
domain
cult to derive
widely
the appropriate,
(i.e., architectural level
it is diffiapplicable
level designs or im-
components)
to make reuse
payoff. ●
nu-
Slowly changing domain technology.
Components
decay over time and rapid changes in underlying
etc. all, to a greater or lesser
have these qualities
new, poorly
What is
Some of the key
reuse are:
Narrow
application
plementation
stood domains like MIS and business systems, user narrowly
target
abstractions
are
cm be highly successful. For example, well underinterfaces,
succes-
from reused components.
attitude
that one can apply reuse to any problem success. The
the
to great benefit.
aspect of the silver bullet
cation domain
with (soft-
kind of question.
to make reuse successful?
of larger components This is another
infrastructure
nor even a completely
factor.
2. Reuse can be applied
within
a process that is inconsistent
sful reuse effort.
organizations, is important
policy and enattitude
factors. An anti–reuse
ware and process) can doom a potentially
of technology
the cultural
and policies
independent
of
our .urocess.
vironmental
reuse or a weak, unsupportive
the degree to which the the
changing
Reuse is sensitive to many cultural, an organization,
it is quite
sensitive to other factors such as the narrowness domain
4. We can have reuse without
domain
technology
(e.g., new models of parallel-
and reuse has flour-
ism) force reusable libraries
Reuse has flopped
depreciate
in
domains.
to decay and thereby,
in value too rapidly to recapture,
ings, the costs to construct
the libraries
in sav-
in the first
place. 3. Reuse
is a hunter/gatherer
successful activity main
activity.
reuse system is largely
of finding standards,
technical
culture.
out into
the field
willy-nilly.
and gathering assembled
●
the right do-
ponents
of well and narrowly zational
defined
goals. Tbo general
ponents
a set
●
or organi-
a set of goals (e.g., we
that support
the need to build inconsistent
such inter-component
compostandards,
on interconnection
Economies
code.
of scale in market.
Build reuse systems
to service areas where there is lots of opportunity to reuse the components.
need a reuse system) or too general a domain (e.g., we need components
reduce
wide stanof the com-
one spends much of the savings from reusing com-
seldom
to accomplish company
Domain
code to connect
nents. Without
up components
are the basis of a high payoff reuse system. Successful reuse systems are crafted
standards.
and thereby,
specialized
of going
libraries
Inter-component
dards enhance the interconnectability
and the right
It is not simply a matter
Casually
a
an intellectual
the right domain, the infrastructure
“Making
because abstractly
all of our func-
ware is being built
Such opportunities
arise
speaking, the same kind of softover and over again.
tional needs) usually lead to a low payoff. The hid●
den truth in this attitude is that populating a reuse library is largely fieldwork and that the gold” is in the domain. lem
driven
But the success comes through harvesting,
establishing
Economies of scale in technologies. Big components payoff better than small components because the interconnections
prob-
defect removal
domain
53
costs are lower and the
costs are lower.
●
Infrastructure
support.
major benefit
Most
through
cess in a well defined The
actual
mated
direct
real role (process
able and quite critical
has an 80 percent
their
manner.
savings
modest.
Reuse in a Medium-Size
of auto-
Nevertheless,
definition)
effect and all of the rest has a 20 per-
cent effect.
the reuse pro-
and unavoidable
productivity
tools is often quite
their
tools provide
establishing
is quite
Wilhelm Schaefer University of Dortmund and STZ Gesellschaft fuer Softwaretechnologie
valu-
to the success of the reuse
process.
A major part of STZ (a medium is building
Some associated
technologies
the above mentioned
that (in the context
factors)
of
enable reuse are
(mostly
Libraries.
The libra~
technology
and delivering
ing a concrete
studies.
reuse by its existence
this software increases
However,
first
response
initiative
is to build
a library
system,
then
have not yet thought
enough
about the
more important
UNIX
they
Modula-2
quality
an experby field
being
in C by partially
systems. The main value of classifi-
terfaces
cation systems is that these systems force the issue the problem
and application
applied
either
in Modula-2
mainly
delivered
in-house.
software
reusing in particular
is written
components’
from
for reuse of interfaces
for or C.
used for building
and evaluated
and tool architectures
Examples
do-
is mainly developed
written
is the language
prototypes
factors.
being produced
workstations
Based on this experience
in-
the prototypes.
(and partly
reuse of
code as well) are especially basic services for the men-
main.
tioned CASE
tools. Their
presentation thereby,
value lies in establishing
system for dealing
including
more abstract
reusable
(and therefore,
a re-
ORACLE
that are
more widely
programming
main value is in the perspicuity tion and its tendency reusable
frameworks) tions).
than in earlier
larized,
In summary, cess model
classes
languages
the object-oriented
tures of technologies,
by a few general
and
from
surefire
but in the end, the details
by hard technical
strong focus on the application
are modu-
types like menu,
of
a
mes-
They can
suitable
this architecture
anew sys-
serves as the basis
design of the new system.
as a basis for
for
support
components,
of
modular
Whenever
@ also
calculating
costs, man
or hindering
reuse in our
etc.)
technology
us away
blocks of our sys-
coarse-grained
case are a very good domain
that
of success and warn
system).
have been predefine.
The major issues enforcing
mix-
in the direction
window
have been defined.
serves b.t.w.
and cultures. principles
terms
for the detailed
or one pro-
It is many different
based on
ones if needed. Reuse of tool architec-
tem is to be built,
months,
process models
failures,
in
architecture
(i.e., func-
point
success are defined
tem
designs.
or one culture.
(either
tures means that the basic building
and
elegant
reuse is not one technology
We can be guided
e.g., specific
more complex
representa-
more
applica-
either be reused as they are or even be used to build
The
of the representa(i.e.,
tends to lead to clearer,
more compact
data base interfaces
The point to make is that these interfaces
reus-
to foster larger and more ab-
components
Further,
languages.
developed
systems (based on X-Windows)
or a selfmade object management
sage, table, selection
Object-Oriented
stract
tools like in-house
and special
with designs and
components
CASE
tion specific window
able) than code.
tion
in software
this is mainly
in
shows
result and has not yet been validated
The software
to a reuse
probably
of understanding
clearly
more than by its functional-
ity. If an organization’s
Classification
and in
producing
imental
that fosters
house)
tools
data base design tools. Our experience
success factor but its value lies largely in establishprocess infrastructure
CASE
particular
and productivity.
is not a primary
size software
customized)
that reuse is producing
other
Software House
also willing
describing
knowledge,
reusable
for developing
a proper
components,
and retrieving
a
these
and last but not least skilled staff who is to reuse other peoples’
work.
analysis and a
and problem
domains.
Understanding
the domain
ture of a tool architecture,
I suspect that there is an 80/20 rule here. The domain
54
means to have a clear pici.e., what are the basic ser-
vicesin
such an architecture
words), what components what components are customized
in other
proaches
have mostly to be adapted,
(orthekemel
software
have always to be there
extensions.
and what
components offers,
ponents,
proper
A clear module
helps a lot in defining interfaces
decompositions.
nology
who haven’t
like modular
decomposition,
abstraction,
functional
pressed in modular ing experienced the knowledge programming
and main-
in this tech-
information
structures.
in writing
hiding, data
In addition,
a lot of uncontrolled bottlenecks
semantic
tricks”
using
structures
thus
side effects. so far are first of all
definitions
The usual informal
of component
descriptions
given
we are aware of the fact that a widely appli-
still an open research
specifications
issue. In addition,
is
it would re-
quire highly skilled staff. The lack of skilled staff is in fact the second bottleneck. ling reuse already modular exploited
A lot of technology
exists (like
enab-
the above mentioned
design, data abstraction
etc.) but it is not yet
because of a serious lack of skilled people
who are able to effectively
apply it.
Software
Kazuo Matsumura Corporation, Systems & Software Engineering Laboratory 70 Yanagi-Cho, Saiwai-Ku, Kawasaki 210, Japan Approaches paradigms
are applied
opment,
and different
methods
development
to Software
stages. Similarly,
proaches to software
at the same
reuse is to cross
Standard
most
general
Approach
Component approach
Approach among
proaches and can be effectively ect. The SCA standardizes and provides develops
all
his software
the basic function
approj-
groups
The programmer
while combining
lacking
is the
reuse
used in real-life
them as components.
nents and creating
(SCA) the
these compo-
functions.
from
the Common
Utility
proach in that the SCA aims at standardizing tion-dependent
functions
while the Common
Approach
only standardizes
low-level
the other
hand, the Program
However,
domain patterns
is
the usage of
this approach can only be used
domains.
The business application
is such an example, because the combination can be relatively
The process control ness application,
easily specified.
application,
is analyzed
SCA is used. The following teristic
On
Approach,
synthesis technique,
to the SCA in that it considers
the patterns.
Utility
functions.
Generator
which is based on component
Ap-
applica-
instead of the busi-
in our study. Thus, the summarizes
the charac-
points of view of the SCA we employed.
1. Application
Domain:
Components
of the products
left unchanged
are aimed to
family, where the ar-
is the same and will be
for a certain
time period
(2 to 5
A component
is a set
years). 2. Definitions of software
of Components: modules prepared
nent consists of programs, and so forth.
Components
for reuse. Acompo-
documents,
test data,
are used not by individ-
uals but by a group of members.
Reuse for software
devel-
are used for different
T~es: Components are Black-box 3. Component and Object-based. Black-box means the invisibili-
ap-
ty of the internal
1 shows typical ap-
for programmers,
there are different
reuse. Figure
The
chitecture
TOSHIBA
Different
Component
be used for a specific product
Software Reuse - What Is Different With Ordinary Development? -
Different
and cultur-
tool support
one after another.
in a few restricted
However,
such formal
Standard
superior
language cause a lot of misunderstandings. enabling
do not always
organizational
time. The major subject of software
The SCA is different
in natural
cable technique
domain.
people be-
C even try to circumvent
about memory internal
the lack of formal functionalities.
just being ex-
by all kinds of “dirty
The major identified
to to
these approaches
methods, and efficient
these hurdles
to use concepts
decompositions
structures
approaches used, according
are only
etc. In many cases, even if they try, results
are purely
modular
like com-
architectural
people
been educated
however,
concept
exist.
In the end, it is hard to convince
Presently,
al background,
such languages
of components
base to
proper
and proper
Of course,
libraries
These
of each application
i.e., compo-
widely accepted if tool support for building taining
the properties
have established
and architectures,
nent interconnections. Modula-2
used.
This issue is highly related
to the second one, namely a proper technology describe
currently
reuse must be selectively
specification
of the components
and thus clarifies
the responsi-
bility for the quality grammers means
assurance without
tamper
with
them.
the implementation
type mechanism. used to abstract
of the abstract
Object-based common
components
resources
and hardware.
therefore,
the object-based
component
plemented
as a package.
The ratio of reuse of components
are
tion on a certain project.
was counted for individual
operational
that
components
ject-based
may be
component.)
The
preparation
and the development different
6.
of components
of products
in terms
component.
are assigned to
components
process
to
The product
architecture
each
obhow-
can be better
of the frequency
In each project,
of use of each
managers felt that the la-
bor of making the components
groups.
5. Development
belong
In view of productivity,
ever, it seems that the effectiveness
as a library.
Organization:
(R should be noted here that
the number of components
evaluated 4.
was about 60 per-
cent or more. Thble 1 shows the results of our evalua-
In Ada,
can be im-
component
and quality is
data
In some ordinary-type
the object-based
implemented
productivity
as follows:
(i.e., objects),
which are found in software
languages,
tion of the SCA concerning
letting pro-
Object-based
would be paid off if the
are used three times or more in average. component-conscious
design and
design in the system design stage should be em-
severe testing decreased the occurrence
of bugs by 20
phasized in advance. This enables the component
percent
development
integration
process to be independent.
Planning/Design planning
Criterion:
In
the
stage, objects are found
tion of the real-time nent classification Then,
SA method.
7. Tmlx
component
at the time of software
Formula
sign) and its support
tools
A)
from objects. invoking
called TFF
for Fifty
Reuse (Project
Next, a comporelaNo of programs
A design technique
system
testing.
Wible 1. Results of Component
are defined.
Description
to 30 percent
by the applica-
table is generated
layers based on component
tionships
In view of quality,
32 modules I program on average
(Technical
steps/module
de-
are used to prepare
components.
1
I60%(*2)
Usage of components What is the Difference? Person level
The SCA has no drastic
departure
proaches toward software
development.
enting
proven
engineering ,rgtiat ion level
methods
key aspects of the SCA from
ap-
in software
be a shortcut
reuse. The following
typical
Thus, implem-
and concepts
would eventually
sful software
from
to succes-
summarizes
the different
some
points of
view Automatic
1. Development
lewl
paradigm:
system framework that of components Figure Evaluation
1. Reusability
of Standard
projects
Approaches
Component
The SCA has been applied
essential
Reuse
to several projects.
are for
medium-sized
several hundreds
of thousands
software
2. Those
containing
(see Figure
Application domain
to narrow rather
of steps. The evalua-
56
domain:
is narrower it down
Both
standardization
for a top-down
approach
for a bottom-up
of and
approach are
2). The
successful
than expected. to a specific
than to cover a broader
application
It is necessmy product
field.
family,
3.
Number
of components:
number
of components
several
hundred
operational grammer
Experience
tells that the
in an adequate
domain
Design
is
to no more than one thousand
components.
However,
knows only a fraction
each
pro-
of this number
at
m
the most. Software System Design B.mction
4. Market
Scale: Software
to those product
reuse would be effective
families
where the products
~%mOnDatd
F=iii=4
are Program Wlgn
manufactured cation
repeatedly.
It would deserve appli-
if three or more manufacturing
expected for the product
cycles are
Module Decomposition Module Specification
Prepared Component (independency/abstraction
Standardize Component
family. Figure
2. Paradigm
of Standard
Component
Approach 5. Interface
between
sign between
components:
components,
bottom-up
design of the component top-down
functional
de-
Especially
a platform
and determining
the extent
of enhancement
would
subjects to facilitate
Ruben Prieto-Diaz Software Productivity Consortium Herndon, VA 22070
as well as
breakdown.
selecting
Reuse in The U.S.
interface
is important
beginning, technical
For interface
at the
Reported
be important
the bottom-up
de-
reuse success stories confirm
Data Services, illustrate
sign.
tors in perspective. technical 6. Introduction
of CASE:
Introduction
lower CASE tools are promising environment
that promotes
of upper/
as a standardized
software
Ted Biggers-
taff’s hyperboles and realities. The three reuse experiences described below, Raytheon, Fujitsu, and GTE
main,
Focus has typically
factors
economic,
the need to keep several fac-
leaving
aside
and cultural
been in the
organizational,
issues. These
doexperi-
ences show that the key to success is the integration these factors
into weli defined
of
reuse programs.
reuse. Raytheon An often quoted
7. Development
cost and management
components
are not obtained
by dividing
existing
software.
tion that the components analysis and review essential.
cost: Useful
just by collecting Under
are used by a third party,
of the components
So managers
or
the assump-
would be
should be reminded
component
development,
maintenance
require
management,
successful
one of the first reported tems Division,
Information
nization
[Lane79].
They
business
application
reuse story and probably
is Raytheon’s observed
that
was established
and reused. A reuse
to analyze their existing soft-
ware and to exploit reuse. Over 5000 production
and
BOL
source programs
were examined
ness applications
to accomplish velopment. ponents, continuous
Managers
standardization
must have a firm will and component
In order to let programmers it is necessary for managers education
regarding
de-
use comto provide
components.
dardized
These logic structures
and a library
fied components New
standard
were stan-
was created to make all classi-
available for reuse. Several modules
were also redesigned tures.
edit, up-
that most busi-
fall into one of three logic structures
or design templates. policy
CO-
and classified.
Three major module classes were identified: date, and report. They also discovered
8. Thorough
6W0 of all
that
their own costs.
Sys-
designs and code were redun-
dant and could be standardized program
Missile
Processing Systems Orga-
to fit the standard
application
logic structures
are slight
logic struc-
variations
of the
and are built by assembling
modules from the library. Programmers use the library
and in the new method
when a logic structure appli~tion.
of recognizing
This program
of the AMI? tion volume
has
for over six years. They report
reuse level were given bonuses of budget ex-
tensions. GTEDS
can be reused to build a new
Reuse is compulso~.
been in operation
certain
are trained to
14!Z0reuse in the first year
Considering
GTEDS
software
(about 700 programmers)
into $1.5 million
an
reported
in savings. Their projected
average of 60% reused code in their new systems and
1995 are 5WZ0reuse with an estimated
a net 5090 increase in productivity.
savings.
Fujitsu
Hyperboles
Fujitsu’s
Software
Development
for
Switching
Systems (SDESS) Program approach
They analyzed
ESSS, cataloged,
mented
each in their
●
to reuse [Hash87].
Information
confirm
programs
change
tions
Center
analysts, software
signs and customers
domain
experts. Library
its original
catalogs.
projects
to formally
ment
reports
(between
software
include
for
by including
in all design and software
●
measured
being on time. Before of 300 projects number
in percent
(AMP)
ISC
the SDEES program
is a corporate
projects
approach
Management
wide program
that
with
analyzing
their existing systems to identi&
features.
GTEDS
reusable assets. Assets are any software (designs, documents,
and select
Wrary
tem.
teams
created
the
library,
reusers. Instead tice, GTEDS rewards.
Narrow
promote
of making
established
Programmers
each component
accepted
of the month”
of incentives
into the libra~
award was established
and Fujit-
Infrastructure
support
is essential.
organizational
All three cases structure
with
All
three
roles.
Extensive
management
support.
dependently
funded.
The library
is a support
directives
and are in-
At
tool not the objective
GTE
DS, for
of a
example,
the
in 1990 it contracted
tired and several others were merged to form sub-
to
systems or packages. Many of these assets are being converted to macros and included into their
prac-
applications
and
to 128. Several assets were re-
generator
can be inserted
directly
Iibraxy was instrumental
where
they
into new applications
environment
The
to arrive at this stage but
it is no longer
essential.
Classification
was instrumental
their
A “reuser
●
for those whore-
used the most, and managers who’s projects
applications
sys-
and royal-
each time
were reused in new projects.
domains are more effec-
business
was
and support
reuse a compulsory
authors
sys-
number of assets in 1988, for example, was 190 and
are paid $50 to $100 cash for
ties were paid to program components
then
reuse,
a program
library
DBMS.
well understood
reuse program.
or to-
The collection
were
●
work product
into an automated
specialized
is not different
and Raytheon’s
spawned from management
ap-
classified and cataloged Five
Center
Fujit-
began
code) that can be partially
tally reused in a new application.
●
[SC87, Prie91].
to reuse is a mix of the previous some novel
of
Program
created to “devel-
in the organization
to
to take advantage
su’s ESS show that to be the case. ●
Asset
de-
suggested
but not essential.
Support library
tive. Raytheon’s
only 20%
With SDEES,
proaches
maintain
is important
specific supporting Services’
had to check previous are (strongly)
tem is based on a typical
to 70Y0.
op a reuse culture” Their
Technology
have a well defined
Data
in all three organizacan be reused before
requirements
su’s Information
GTE DS GTE
develop-
in software
of current
were on schedule.
increased
their
than a regular
reviews. Fu-
improvement
and designers
software
and com-
all software
●
development
points:
existing designs.
and
the ISC in their develop-
is accomplished
a significant
modify
reference
software
archives,
It is compulsory
cycle. This
staff members jitsu
staff roles include
designers),
mercial
reuse experts, and ESS
support
the
have to check what
coding
desk, cross reference
the following
ment process. Programmers
and docu-
Support
Reuse
(ISC). The ISC is a regular library staffed with systems engineers,
in
has taken a sim-
pler and more pragmatic previous
figures for
$10 million
and Realities
These experiences
Electronic
produc-
this translates
and structuring
achieved
ger in the Raytheon
58
in understanding
the domain. The evidence is stronand GTE DS experiences.
●
All three are financially
To answer the panel’s
successful.
presented
confirms
evaluation
that current
level four when implemented These and other not as widely reported periences
(e.g., AT&~
Hartford
have led
to start their own corporate
programs.
them
Packard, SAIC, Dynamics,
comprehensive ganizational,
Boeing,
and Harris.
are: IBM, Hughes,
domain,
Motorola,
to make reuse programs ments in these programs
References [Hash87]
Hashlmoto,
ing visit to Fujitsu
K. Company
presentations
dur-
Ltd., Tokyo, June 1987.
issues.
[Lane79]
Lanergan,
R.G. and Poynton,
able Code The Application of the Future.”
In Proceedings
GUIDE
Software
October
1979.
[Prie91]
Prieto-Diaz,
B.A. “Reus-
Development
Symposium,
Technique
of the IBM IBM,
SHARE/
Monterey,
CA
in models and techniques Initial
invest-
have been high in time and informally.
technology
and productivity
capable we are at implementing hensive reuse programs
at
properly.
General
trend towards
more efficient.
of reuse as an effective quality
Hewlett
and cultural
money, and have been implemented ing software
reuse
that also address or-
economic,
There is a need and interest
future
Contel,
This is a definite
reuse programs
reuse is delivering
and practiced
successful ex-
Insurance)
some organizations Among
scale, the evidence
The
Classification
for Software
of the ACM,
(April
“Implementing Reuse”
Faceted
Communications
1991).
for improv[SC87] Swanson, M.E.
depends on how
efficient
R.
and S.K. Curry,
ing an Asset Management
and compre-
vices.” Information
at low cost.
59
Program
Management
“Implement-
at GTE Data SerVol 16, 1989.