A prototype software system was developed for the U.S. Naval Underwater Systems Center(NUSC) as a demonstration of the Cleanroom Software Engineering methodology. The Cleanroom method is a team approach to the incremental development of software under statistical quality control. Cleanroom's formal methods of Box Structure specification and design, functional verification, and statistical testing were used by a four-person team to develop the Automated Production Control Documentation(APCODOC) system, a relational database application. As is typical in Cleanroom developments, correctness of design and code were ensured through team reviews. Eighteen errors were found during functional verification of the design, and nineteen errors were found during walkthrough of the 1820 lines of FOXBASE code. The software was not executed by developers prior to independent testing (i.e., there was no debugging). There were no errors in compilation, no failures during statistical certification testing, and the software was certified at the target levels of reliability and confidence. Team members attribute the ultimate error-free compilation and failure-free execution of the software to the rigor of the methodology and the intellectual control afforded by the team approach.

Abstract The theory for local software quality metrics that appeared in Software‐Practice and Experience in November has been tested in field experiments. Data collected in the experiments and the results are presented here. The theory prescribed two activities, one for articulating rule sets for quality and the other for deriving a statistical metric. The process of deriving the statistical metric has been reduced to easy practice. Effective articulation of rule sets is still under study.