Information Technology Reference
In-Depth Information
Alpha testing
involves testing an incomplete or early version of the system;
beta test-
ing
involves testing a complete and stable system by end users. Alpha-unit testing, for
example, is testing an individual program before it is completely finished. Beta-unit testing,
on the other hand, is performed after alpha testing, when the individual program is complete
and ready for use by end users.
Unit testing is accomplished by developing test data that will force the computer to
execute every statement in the program. In addition, each program is tested with abnormal
data to determine how it will handle problems.
System testing requires the testing of all the programs together. It is not uncommon for
the output from one program to become the input for another. So, system testing ensures
that program output can be used as input for another program within the system. Volume
testing ensures that the entire system can handle a large amount of data under normal op-
erating conditions. Integration testing ensures that the new programs can interact with other
major applications. It also ensures that data flows efficiently and without error to other ap-
plications. For example, a new inventory control application might require data input from
an older order processing application. Integration testing would be done to ensure smooth
data flow between the new and existing applications. Integration testing is typically done
after unit and system testing. Metaserver, a software company for the insurance industry,
has developed a tool called iConnect to perform integration testing for different insurance
applications and databases.
Finally, acceptance testing makes sure that the new or modified system is operating as
intended. Run times, the amount of memory required, disk access methods, and more can
be tested during this phase. Acceptance testing ensures that all performance objectives defined
for the system or application are satisfied. Involving users in acceptance testing can help them
understand and effectively interact with the new system. Acceptance testing is the final check
of the system before start-up.
alpha testing
Testing an incomplete or early
version of the system.
beta testing
Testing a complete and stable
system by end users.
Start-Up
Start-up
, also called
cutover
, begins with the final tested information system. When start-up
is finished, the system is fully operational. Start-up can be critical to the success of the orga-
nization. If not done properly, the results can be disastrous. In one case, a small manufacturing
company that decided to stop an accounting service used to send out bills on the same day
they were going to start their own program to send out bills to customers. The manufacturing
company wanted to save money by using their own billing program developed by an em-
ployee. The new program didn't work, the accounting service wouldn't help because they
were upset about being terminated, and the manufacturing company wasn't able to send out
any bills to customers for more than three months. The manufacturing company almost went
bankrupt.
Various start-up approaches are available (see Figure 13.12).
Direct conversion
(also
called
plunge
or
direct cutover
) involves stopping the old system and starting the new system
on a given date. Direct conversion is usually the least desirable approach because of the
potential for problems and errors when the old system is shut off and the new system is turned
on at the same instant.
The
phase-in approach
is a popular technique preferred by many organizations. In this
approach, sometimes called a
piecemeal approach
, components of the new system are slowly
phased in while components of the old one are slowly phased out. When everyone is confident
that the new system is performing as expected, the old system is completely phased out. This
gradual replacement is repeated for each application until the new system is running every
application. In some cases, the phase-in approach can take months or years.
Pilot start-up
involves running the new system for one group of users rather than all
users. For example, a manufacturing company with many retail outlets throughout the coun-
try could use the pilot start-up approach and install a new inventory control system at one
of the retail outlets. When this pilot retail outlet runs without problems, the new inventory
control system can be implemented at other retail outlets. Google's personal health records
application was tested as a pilot project in a Cleveland health clinic before it was made
start-up (also called cutover)
The process of making the final
tested information system fully
operational.
direct conversion (also called
plunge or direct cutover)
Stopping the old system and starting
the new system on a given date.
phase-in approach (also called
piecemeal approach)
Slowly replacing components of the
old system with those of the new
one. This process is repeated for
each application until the new
system is running every application
and performing as expected; also
called a piecemeal approach.
pilot start-up
Running the new system for one
group of users rather than all users.
