Is the need for measurement an admission that formal methods are not perfect?

The strategic significance of system and software quality to industry, commerce and the community at large is now widely recognised by all, including government. Two main philosophies are currently pursued to quality assurance: the accreditation procedure of the software development process itself through schemes such as BS5750 and the proof of software correctness through the use of formal methods. The authors explore the extent to which these philosophies singly or collectively, satisfy industry´s obligation to produce high quality software