defined as sub characteristics. More specifically, the
‘Testability’ is belonging to the ‘Maintainability’ is
belonging to the ’Usability’ characteristics and the
‘Interoperability’ is belonging to the ‘Functionality’
characteristics. One of the important security attribute has
been added by ISO 9126 [39], which cover the Reliability,
Confidentiality and Integrity. Without Reliability and
Security, it is not possible to achieve the quality of
software product. In literature we found that quality
models attempted to evaluate several quality
characteristics but failed to provide reasonable accuracy.
We believe that quality models must evaluate high-level
quality characteristics with accuracy in terms, well known
to software engineers to help maintainers in assessing
programs.