AbstractThis paper describes the use of Shewhart U charts for controlling software quality while the software is under development. A parallel between the software development process and a complex manufacturing process is developed. This allows the use of statistical control charts to monitor the software development process.The general approach is to let observed defect data represent a sample of the true but unknown state of the entire software project. Software quality data so obtained can be used to derive a meaningful statistical interpretation of the state of the development project. Based upon this interpretation management can take action to improve the overall software quality while in the development stages.