Understanding Requirements - Requirements Engineering and Management for Software Development Projects - page 16

Controlled (CNC) machines not only in workshops but also in homes do have
this limitation. In the present era, the cars, the refrigerators, the washing
machines, the ovens, the mobile phones all have software on a chip which
have limited capacity. This calls for restrictions on the size of the software that
can be installed on the chip. This information can be obtained from the
hardware manufacturers supplying the selected chips on which the software is
going to be installed.
9. Fault tolerance functionality—Users make mistakes in using software, mostly
unintentionally. This functionality ensures that software does not crash or abort
when a mistake is committed by the user. It provides an error message and
provides an alternative path and allows the user to use other functionality
besides coming out of the fault-scenario smoothly without causing any damage.
10. Reliability functionality—There is a misconception in some quarters that
since there are no moving parts, software ought to function reliably if it
correctly runs once. But in these days of fast obsolescence, this becomes
applicable. Every 3 years a new version of the operating system, browser, and
middleware are released. The hardware, including processors, Network
Interface Units (NIUs), switches, etc. are also upgraded every now and then.
Since most modern applications work on the Internet the threat of viruses,
spyware and malware also increased significantly. Any of these can impact the
way our software works. Therefore, it is important to build the software in
such a way that some of the possible changes do not affect the software or
provide functionality to indicate that the environment changed so that cor-
rective action could be taken. The users should not be faced with a software
failure to understand that it needs upgrade. Software failure due to environ-
mental change needs to be trapped and an alternative path needs to be
available for the users for smooth changeover or closure of the application.
11. Feel-good functionality—This functionality is making the user interface look
jazzy and sexy. The idea is to make the users feel good while using the
software. This is adding glitz to the user interface screens and using nice
pictures for buttons and icons and so on. I know of software product failure
because the screens are not sexy!
12. Esteem functionality—This functionality brings pride to the users. For
example, a Rolex watch delivers the same core functionality (showing time) as
any other watch. But by ensuring that the thicker gold plating of the casing,
scratch-proof crystal and so on, Rolex watches bring pride to the owners albeit
at a higher cost. In software too this kind of functionality can be brought in the
form of better messages, handling of error conditions, adding functionality
that no other software possesses and so on.
13. One-upmanship (competitive edge) functionality—This functionality gives
competitive edge to the software. It is having more functionality than any of
the competitive software packages possesses. This functionality may be in
core functionality or ancillary functionality. Compared feature to feature, this
package would have one or more functional aspects in every feature over the
competitive software packages.