  This work proposes a methodology for source code quality and static behaviour
evaluation of a software system, based on the standard ISO/IEC-9126. It uses
elements automatically derived from source code enhanced with expert knowledge
in the form of quality characteristic rankings, allowing software engineers to
assign weights to source code attributes. It is flexible in terms of the set of
metrics and source code attributes employed, even in terms of the ISO/IEC-9126
characteristics to be assessed. We applied the methodology to two case studies,
involving five open source and one proprietary system. Results demonstrated
that the methodology can capture software quality trends and express expert
perceptions concerning system quality in a quantitative and systematic manner.
