Understanding Requirements - Requirements Engineering and Management for Software Development Projects - page 19

have originated there. In software industry, re-usability is rather an exception
rather than a rule. But it pays to implement this concept in software products
too. These are non-functional requirements and are normally covered by
standards and guidelines or the organization.
5. Portability—In earlier days, porting is referred to as shifting the software
developed in the same language such as COBOL from one hardware platform
to another. But now, such a thing is passé. But another type of porting has come
on to the scene. It is shifting the web site from one host to another. With cloud
computing, it would be much more frequent in the future to be shifting
applications from one host/data center to another. The functionality specifica-
tions focused on ensuring that the impact of porting is minimized come under
this category and include standards and guidelines for achieving the portability.
6. Operations ease—Modern software products are large and multi-functional
systems involving many users, perhaps, from different geographical regions
spanning international borders. To keep such systems operational round the
clock, they need specialists running the operations. Therefore, many of them
need dedicated/shared systems administrators, DBAs and network administra-
tors. In many cases, updating the software or hardware has to be achieved
without bringing down the systems. Therefore, the software product needs to be
built keeping all these aspects in consideration. These aspects are covered
normally by the standards and guidelines dealing with product architecture,
design and construction.
7. Testability—Of course, the product has to be testable and will be so. What is
so special about testability then? It is generally agreed that 100 % testing of
large software products is not practicable. Therefore, a variety of quality
assurance activities are implemented during software development. The cost of
fixing defects varies proportionately with the stage in which the defect is
uncovered. A defect uncovered during unit testing costs much less to fix than a
defect that is uncovered during system testing stage. The final product is always
testable but what is sometimes becomes difficult to test is, the software unit/
component. The software product has to be designed and built in such a way
that every software unit is independently testable in a stand-alone manner.
Testability requirements are normally covered by the standards and guidelines
dealing with software architecture, design and construction guidelines.
8. Interface functionality—In these days of web based Internet applications,
interfacing becomes essential. The internet itself is built with multiple layers.
There are many browsers, and different servers, ISPs and networking protocols
that an Internet application has to interface with. Additionally, the applications
need to be built in such a way that it would be possible to interface with
applications that the organization may build later on. This kind of functionality
would be covered under standards and guidelines dealing with software design
and construction, normally.