Selecting the development environment and tools
EXSYS Professional, by EXSYS, Inc., was selected as the expert system
building tool to develop UNU-AES. This software package was chosen
because of a combination of several factors. The first is the requirement of the software to run under MS-DOS (an operating system) and to operate on
a portable computer. Having the expert system operate on a portable
computer under MS-DOS was a necessity because of its potential demonstration
and use in developing countries. Secondly, it is important that the
program be simple enough so that an end user can learn to run the program
and perform sensitivity analyses with a minimum amount of training time.
The third consideration is based on the wealth of powerful features of the
software tool. Chief among these features were its screen definition language
(to customize the way questions are asked) and its ability to allow interface
calls to external programs. EXSYS Professional also provides an explanation
facility to assist the system user.
Turbo Pascal, by Borland, Inc., was selected as the software package to
create the screen graphics. The reasons this software package was chosen are
because it fulfilled the operating system and target computer requirements,
it could be accessed from EXSYS via external program calls, and it offered
the developers a set of tools to develop the color screens. Examples of the
UNU-AES screen graphics are illustrated in Figures 5-7.