Information Technology Reference
In-Depth Information
farmers of large farms pay considerable attention to what fertilizer is
needed on what parts of their fields. Applying too much fertilizer may
contribute to the pollution of ground water, as well as costing money
for little gain. Applying too little fertilizer reduces crop size, generating
less income. To address this situation, farmers often take soil samples
from various parts of their fields and perform tests to determine the
optimal amount of fertilizer to be applied in each area. Unfortunately,
the desired quantity of fertilizer often differs from one part of a field
to another, and it is impractical to manually adjust the amount of fer
tilizer dispersed from the spreader while a tractor moves through a
field. (The farmer would have to stop the tractor, make an adjustment,
drive a bit more, make another adjustment, and so on.) Such a situa
tion led to the vision that a computer might use a Global Positioning
System (GPS) to keep track of the tractor's location in the field and
make adjustments as the farmer drives. As you might expect, develop
ment of such a system required working through many details, such as
determining specific needs, practical constraints, and numerous
elements of farming equipment. Even with such complexity, modern
systems are available to control fertilizer application based on this
broad vision.
At other times, we may believe that there is a market for a new
software package that would perform a particular task and want to
create it. For example, when computers were just coming into peo
ple's homes, most people maintained records of their bank accounts
manually on paper. For a checking account, an individual would
record deposits, withdrawals, and any fees as they occurred. With
each transaction, the individual would add or subtract the relevant
amount to obtain a new bank balance, and this running balance was
compared with a statement received monthly from the bank.
Although the process was supposed to be fairly straightforward,
transactions sometimes were forgotten or misrecorded, and arith
metic errors were not uncommon. Locating such problems often re
quired considerable time and effort. Because computers seemed to be
effective in storing and retrieving information and in doing arith
metic, it seemed likely that the computer might be helpful in this
recordkeeping effort. After identifying the basic problem of main
taining account records, the program developers had to consider just
what functionality users might want, what types of input and display
would be most helpful, what legal constraints or accounting stan
dards might apply, and so forth. The idea of a software package re
quired considerable discussion and clarification before developers
