Cleanroom SE summary and review
Focus is on high quality software through preventing defects.
Case studies show it produces software with drastically fewer defects. Case studies also show high productivity and group morale.
It requires major changes in ways to approach software:
formal correctness proofs and counting compiler errors as defects are two notable.
It can be adapted to work with structured approaches or OO methods, with some changes.
Testing depends on statistical use testing - a probabilistic model of how it is used - which produces "certification" of components.
It requires training and on-site "experts" to be effective (at least at first.)
It is a rigorous and formal approach to software engineering that produces very reliable software that most other software engineering methods can not produce.