The Rome Laboratory TR-92-52 Software Reliability Measurement model was originally developed in 1987 and updated for the last time in 1992. It was one of the first models to predict software reliability before the code is written. It does so by correlating many software development practices to defect density. This model was built entirely for the defense industry. The Softrel models are based on the same basic principals as the Rome Laboratory model except that the data is current and is inclusive of several industries. Several parts of the model are outdated including the baseline average defense densities by application type. However, several of the "factors" can still be used today for calibrating historical data.
Rome Laboratory TR-52 software defect density prediction