In this, the
last of a series
of'columns on I-
CASE technolo-
gy, we discuss
the improve-
ment in produc-
tivity that can
be realized with .
the use of CASE
tools. s
To achieve

in building com- ,

puter applica-

tions, it's neces-
sary not only to select the best CASE
and ICASE (integrated computer-aided
software engineering) tools, but also to
adapt your organization and methods to '
take full advantage of these tools.

The simplest CASE tools are little '

. "more than diagramming aids. They sim-

plify the drawing of diagrams and en-

able them to be kept tidy,and modified ;:;;

guickly.
Code generators enable implementors
to produce a working program guickly.'

However, if the generator is not linked"

to a dictionary, data model or design
tools, the programs generated may be
incompatible fragments, kosnsieti ML
not linked together. :

To achieve high Productivityi the nani
for design need to be tightly coupled to
the code generator. The tools should em-
ploy a data model and should enable

the design to be represented in a power: <;;

ful, visual, easy-to-modify form from
which code is generated directly. .

The programs sliould be guickly exe'''i?

cutable so that the designer can observe
what they do, adjust or add to the de:
sign, rerun the programs, enhance the
design and so on, until a comprehensive
system is created. B

The principle of "what you see is ' di

what you get" should apply to-the co:
bination of visual design tool and code '
generator. The need for manual coding '

of procedures should be removed to the ši

maximum extent.

The generator may initially be used to...

produce structured code that relates to ('
the design sereens. This code may be
used for prototyping and debugging. Be- ;

cause structured code does not give opti- '

mal machine performance, for heavy-

duty applications the code may be fed.../.

into an optimizer, which creates code

with optimal machine performance. This ,:,

, code will never be touched by mainte-
nance programmers; all maintenance is
performed at the specification level."

'The integrated designer-generator tool Vi
should aid in rapid construction and

modification of prototypes. It should |

generate test data and provide testing
o oboki penerate database, pode li
and job-control code, so that the pro-

be emo dek she] ;
sign changes are made. <ki

strongly affected by the number of peo-

high productivity

Productivity in system development is. projects. The flow of data and control.

Modity Your Methods ITo Take 'Advantage of I-CASE Tools

grammers. As shown in the figure, con-

" ventional technology often reguires
— large development teams and long devel-

opment eycles. In contrast, many pro-
jects or subprojects developed with I-
CASE tools can be completed by one
person. The brilliant, fast or hard work-
ing individual then has the opportunity
to excel. Management should encourage
the most capable implementors to learn
the full power of an I-CASE tool set in
order to maximize productivity. ;

Big projects should be subdivided into
small projects, each of which can be

: completed. relatively guickly by one, two
0 | or, at most, three implementors. The

CASE tool should make it possible to de-

h
O
w
p
5
Z

Single Person -
-CASE Project

components šhould be catalogued in a
CASE encyclopedia so that they can be
selected when needed and modified as

-reguired.

A large enterprise should employ the
same ECASE tool set at all locations
where systems are built so that common
data models, designs and program com-
ponents can be used. Telecommunica- |
tions access to mainframe encyclopedias
aids in the sharing of applications, docu-
ment design, accounting procedures and,
so on. ! |

In systems developed by traditional
manual technigues, maintenance is a
major problem. Systems are often diffi-
cult and time'consuming to change. Af-

Productivity Economy with
I-CASE Technology

Convehtiorial
Multi-Persoti

met' projebt

ii

fe

ite sleni: pone Bl

| fine with computer precigion the, inter-

faces between the components PESA
ed by separate teams. pit

V At the start of a large project, an enti-
ty-relationship raketi opran be creat
| ed for the data that will be used, the
V dam elements should be sein dnd. te

correctly prilepi

data model should be used for mi gub-

HE MOJ,

| ter being modified many times, they of-
ten become fragile; even minor changes
result in bugs and breakdowns.

A goal of I-CASE tool sets is to pro-
duce systems that are guick and easy to

change, Maintenance isn't done by dig-
the. ging around in spaghetti code but. by
"91 V". modification of the design specifications,

FEBRUARY 13, 1989 -

reguired. When changes are made to the

design, the encyclopedia is automatically

updated.

The use of I-CASE tools avoids the
spaghettilike mess of the past and pro-
motes cleanly structured engineering
with relatively fast and easy technigues
for maintenance.

Although in some corporations the
main thrust with CASE tools is to in-
crease the productivity of application
building, in others the goal is to improve
the guality of systems and achieve coor-
dination across a complex enterprise.

The most impressive system is not
created with a single design and imple-

, mentation. It evolves, being improved in
many steps at different times and
places.

The future will bring impressive soft
ware and corporate computer systems,
and these will also be grown over many
years with many people and organiza-
tions adding to them.

It's difficult or impossible to grow
software that's a mess. To achieve long:
term evolution of software, we need
 structured models of data and struc-
tured models of processes.

Designs too complex for one person to
know all the details of must be repre-
sented in an orderly fashion in an ency-
clopedia so that many people in many
places can add to the design. The design
needs standards and reusable compo-
nents and an architecture that facili-

, tates the incremental addition of new
funetions.

For executives to control the behavior
of computers that automatically place
orders, select suppliers, make trades and
so on, the behavior of these systems
should be expressible in rules and dia-
grams that, the executives understand.

When It Works, It Really Works
Some corporations have impressive
computer systems designed to give them

a competitive advantage: Take Ameri-
can Airlines with its on-line terminals in
travel agents' offices, or Benetton with
its worldwide information system that
makes the world activities "transparent"
to the decision makers near Rome.

Systems like these demonstrate how a
corporation can pull ahead of its compe-
tition by using information and automa-
tion better. Efficient, corporations will
evolve computing systems that are
worldwide and exceedingly complex,
but nevertheless enable procedures to be
adapted guickly to changing needs.

To do this reguires engineering-style
methodologies carried out with automat-
ed tools. It reguires encyelopedia-based
[CASE tools. Simple software engineer-
ing is not enough—to build a computer-
ized corporation we need information
engineering. 8

The James Martin Productivity prsa
an information service updated guar-
terly, is available through High Pro-
ductivity Software Ine., of Marble-
head, Mass. (800) 242-1240. For infor-
mation on seminars, contact (in the
United States and Canada) Technology
— Transfer Institute, 741 10th St., Santa
ploelen GOJE 90402 (213) 394-8305.
e, contact Savant, 2 New St., |