ADOPTING CLEANROOM SOFTWARE ENGINEERING WITH A PHASED APPROACH

Cleanroom software engineering is a theory-based, team-oriented engine ering process for developing very high quality software under statisti cal quality control. The Cleanroom process combines formal methods of object-based box structure specification and design, function-theoreti c correctness verification, and statistical usage testing for reliabil ity certification to produce software approaching zero defects. Manage ment of the Cleanroom process is based on a life cycle of development and certification of a pipeline of user-function increments that accum ulate in the final product. Teams in IBM and other organizations that use the process are achieving remarkable quality results with high pro ductivity. A phased implementation of the Cleanroom process enables qu ality and productivity improvements with an increased control of chang e. An introductory implementation involves the application of Cleanroo m principles without the full formality of the process; full implement ation involves the comprehensive use of formal Cleanroom methods; and advanced implementation optimizes the process through additional forma l methods, reuse, and continual improvement. The AOEXPERT/MVS(TM) proj ect, the largest IBM Cleanroom effort to date, successfully applied an introductory level of implementation. This paper presents both the im plementation strategy and the project results.