Zero Defect Software: Cleanroom Engineering

Abstract

Publisher Summary Software is either correct or incorrect in design to a specification, in contrast with hardware that is reliable to a certain level in performing to a correct design. Certifying the correctness of such software requires two conditions—namely, statistical testing with inputs characteristic of actual usage, and no failures in the testing. Cleanroom Engineering introduces new levels of practical precision for achieving correct software, using three engineering teams—namely, specification engineers, development engineers, and certification engineers. Software can be developed and certified as correct under statistical quality control (SQC) to well-formed specifications of user requirements. The chapter discusses history and application of SQC to software development. Two major properties of Cleanroom Engineering are: no debugging by the developers before the software goes to independent testers and statistical testing taking into account both the usage and the criticalness of software parts. Cleanroom software engineering achieves statistical quality control over software development by strictly separating the design process from the testing process in a pipeline of incremental software development. There are three major engineering activities in this process are software specification, software development, and software certification. The chapter elaborates the statistical quality control in software engineering. Markov chain techniques for software certification are discussed. The cleanroom engineering methods are outlined. Box Structured Software System Design is discussed.