Establishment of Requirements - Requirements Engineering and Management for Software Development Projects - page 72

T able 5.1 (continued)

IEEE. If you expand the acronym SRS as ''Software-Requirements Specification''
(combining the first two words), the meaning would become clearer. It is the
specification document detailing the requirements for the software product/system
from the technical perspective. Perhaps, it would be even more lucid if we term it
as ''Software Product Specification'', but it would be adding another term to the
already bulging vocabulary of software engineering.
SRS is derived from the requirements specified by the end-users in the URS.
While URS documents requirements from the perspective of the end-users, SRS
documents requirements from the perspective of the product. SRS is the statement
of technical specifications for the proposed software product. SRS is the main
reference for the product designers in carrying out the design of the proposed
software product/system along with other organizational standards and guidelines
for software design.
Prototype is often used to supplant SRS in some organizations. Those organizations
document user requirements in the URS and build a prototype instead of deriving and
documenting the software requirements. The main advantage of doing so is that the
end-users can better perceive the proposed software product/system when presented
with a prototype rather than a SRS document. The downside of building a prototype is
that much more effort needs to be spent in building a prototype than in documenting
SRS. Second, if the user-requirements are poorly understood, the prototype may have
to undergo major changes and it would consume significant effort in overhauling the
prototype than it would take in overhauling a SRS document.
Prototype is used heavily in product development in the manufacturing
industry. When it is contemplated to build a number of products with the same
design, such as automobiles, it is common practice to build one car with the design
and subject it to all necessary tests. When the prototype successfully passes