Important quality attributes and their definitions

Summary

Quality Attribute	Definition
Understandibility	The ease with which the design fragment can be comprehended
Changeability	The ease with which a design fragment can be modified (without causing ripple effects) when an existing functionality is changed.
Extensibility	The ease with which a design fragment can be enhanced or extenended (without riple effects) for supporting new functionality.
Reusability	The ease with which a design fragment can be used in a problem context other than the one for which the design fragment was originally developed
Testabillity	The ease with which a design fragment supports the detection of defects within it via testing.
Reliability	The ease with which the design fragment supports the correct realization of the functionality and helps guard against the introduction of runtime problems.