54 Part I • Information Technology
storage format, integrity rules, security clearances, and
physical location of data need to be discovered. The DD/D
is similar to an inventory accounting system for a parts
warehouse—but in this case for a data warehouse, or a
database. Many modern DBMSs have a built-in DD/D
capability.
CASE Tools
It was originally predicted that CASE tools—our fourth
type of support software—would have a major impact on
computer professionals, and that has been true for some
professionals in some firms. However, the growth of the
use of CASE tools has been much slower than anticipated.
Computer-aided software engineering (CASE)is actu-
ally a collection of software tools to help automate all
phases of the software development life cycle. (The life
cycle for software development is discussed in Chapters 8
and 9.) In those firms that have adopted CASE tools,
CASE has radically changed the jobs of systems analysts
and programmers. In particular, the job of the analyst or
programmer involves more up-front work in clearly defin-
ing the problem and expressing it in the particular specifi-
cations required by the CASE tool. Then the tool assists in
the back-end work of translating the specifications to
the required output, such as a data flow diagram (see
Chapter 8) or a COBOL program.
There has been a recent surge in the use of CASE
tools for object-oriented development based on the
Unified Modeling Language (UML).UML is a general-
purpose notational language for specifying and visualizing
complex software, especially large, object-oriented proj-
ects. Examples of such UML-based CASE tools are IBM
Rational Software Architect for WebSphere and IBM
Rational Rhapsody, Borland Together (from Micro Focus,
based in the United Kingdom), and Sybase
PowerDesigner. We will defer a more complete treatment
of CASE software until Chapter 9, where we will explore
the role of CASE tools in the systems development
process. For now, note that CASE is only beginning to
make an impact. CASE has the potential of providing a
productivity boost to an area of the company (the informa-
tion systems organization) that needs such a boost.
Communications Interface Software
Communications interface software, our fifth type of sup-
port software, has become increasingly important with the
explosion in the number of local area networks (LANs)
and wide area networks (WANs) and with the growing
importance of the Internet and the World Wide Web. We
have already discussed perhaps the most important type of
communications interface software, the Web browser,
which is software that runs on the user’s computer
enabling the user to look around, or “browse,” the Internet.
The communications interface software on the server to
“serve” the Web pages to the browser is called, appropri-
ately enough, Web server software. The most popular Web
server software is Apache, an open source product from
the Apache Software Foundation, which is available for a
wide variety of operating systems, including Linux,
various versions of UNIX, and Windows. In 2010, Apache
was running on over 110 million Web sites (Netcraft,
2010). Another valuable communications interface prod-
uct is File Transfer Protocol (FTP).This product is
designed to transfer files from one computer system to
another. In effect, the user logs into the two computer
systems at the same time and then copies files from one
system to the other. The files being transferred might be
programs, textual data, images, and so on.
Communications products on large computers with
many attached workstations have the awesome task of con-
trolling the communications of these workstations, or ter-
minals, with the central computer. This software collects
the messages from the terminals, processes them as neces-
sary, and returns the responses to the proper terminals.
These products are often designed to work closely with a
particular operating system. For example, IBM’s CICS
(Customer Information Control System) is a communica-
tions product designed to work with IBM’s z/OS operating
system. IBM has also created versions of CICS that work
with AIX, IBM’s UNIX operating system; Solaris, Sun’s
UNIX operating system; HP-UX, Hewlett-Packard’s
UNIX operating system; and Microsoft Windows Server.
Other types of communications interface software will be
mentioned in Chapter 3 when we explore telecommunica-
tions and networking.Utility Programs
Our final type of support software is obviously a catch-all
category, but an important one nevertheless. On large com-
puters, utility software includes programs that load applica-
tions programs into an area of memory, link together related
programs and subprograms, merge two files of data together,
sort a file of data into a desired sequence (e.g., alphabetical
order on a particular data item), and copy files from one place
to another (e.g., from a DASD to magnetic tape). Utility pro-
grams also give the user access to the software library. In
most cases, the user communicates with these utility pro-
grams by means of commands in the job control language.
On a microcomputer, utility programs are used to zip (com-
pact) and unzip large files for easier transport, to reorganize
the hard drive to gain disk space, to check for computer
viruses and spyware, and for many other tasks.