Cleanroom software engineering

Cleanroom software engeneering is available for the development of high-quality software. It is based on a set of formal specifications describing the external behavior of the system.The focus of Cleanroom involves moving from traditional software development practices to rigorous, ngineering-based practices.The goal of Cleanroom software development is to be able to develop software with zero failures in the field.
Cleanroom can be applied to new systems as well as existing systems. For example, poor quality sections of software in existing systems can be re-engineered using certain Cleanroom techniques such as formal correctness verification.