Quality Assurance in Requirements Management - Requirements Engineering and Management for Software Development Projects - page 89

Chapter 6
Quality Assurance in Requirements
Management
6.1 Introduction to Quality Assurance
The word ''quality'' has multiple meanings and connotations. It means ''character'',
''inherent feature'', ''degree of excellence'' and ''distinguishing attribute'' among
others. In the present context, we refer to ''degree of excellence'' as the meaning of
the term ''quality''.
Quality is a term that is often used without any adjectives like good or bad. We
often say ''It is a 'quality' product'' meaning that the product has superior or better
than average quality.
International Organization for Standardization (ISO) defined the word ''quality''
as ''the degree to which a set of inherent characteristics fulfills requirements. The
term 'quality' can be used with such adjectives as poor, or good or excellent.
'Inherent' as opposed to 'assigned' means a permanent characteristic existing inside
something.''
Another popular definition of ''quality'' by Joseph Juran is ''quality is fitness for
use''.
These two definitions have practical implications for implementation. Juran's
definition leaves the terms ''fitness'' and ''use'' undefined. Unless these two terms
are defined, the definition is open to misinterpretation by users and producers of
goods and services and they often do. The ISO definition makes ''quality'' a
continuum and usage of adjectives is mandatory. But most of us are used to using
the term ''quality'' without any adjectives to mean good quality. Again the terms
''good'', or ''bad'' or ''poor'' or ''excellent'' are vague terms not lending them-
selves to quantification or measurement.