Information Technology Reference
In-Depth Information
There are many other companies besides VMware in the virtualization business
sector. This is an interesting example of a new kind of market niche that exists
only because of computers and software.
In general, the software companies cited here are expanding the uses of com-
puters and software into new directions. Several of the companies cited could not
have existed 20 years beforehand because the internet and the World Wide Web
were needed in order to carry out their business models.
Mass Updates and Aging Legacy Software
Business and commercial software applications began to expand in numbers by
1975. By the middle of the 1990s, some applications, such as IBM's operating sys-
tems, had been evolving and used for more than 20 years. The same was true for
other industries and applications that had been early adopters of computers and
software: banks, insurance, telecommunications, and a number of others.
The increasing age of many important software packages introduced a new
phrase into software engineering: “legacy applications.” The large volume of
aging legacy applications would soon play a part in a new kind of software prob-
lem called
mass updates
that require changes to thousands of legacy applications
simultaneously. (Mass updates occur when problems, such as the one that Y2K
posed, that affect thousands of applications need to be changed at the same time.)
This type of problem is going to stay with us from now on and will get worse in
the future.
The task of maintaining aging legacy applications would grow rapidly and by
2000, software maintenance would absorb more software engineering time than
software development. This is not unexpected and has occurred in other industries.
By the time automobiles had been in use for 30 years, there were more mechanics
who maintained automobiles than there were assembly line workers building new
automobiles.
Consider the software world as it neared the end of the decade, say from 1995
on. The new euro currency was about to be introduced in 1999. The famous Y2K
problem would occur as the calendar changed from 1999 to 2000 at midnight.
Neither of these issues is a problem for new applications, but both were serious
problems for the huge inventory of aging legacy software packages.
Both of these topics would impact thousands of legacy applications that had
been running for many years. They would require the diversion of thousands of
software engineers and millions of staff hours to modify aging applications. These
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