The Defect Tuning Factor is a scaling parameter that tunes SLIM-Collaborate’s reliability estimation model up or down to match your historical defect discovery data. For each Closeout project that completes, you can enter the final Defects (SIT-DEL) total on the Actual Data tab of the project. SLIM-Collaborate uses this data to calculate a defect tuning factor that can be used to tune future reliability estimates to match one or more of your completed projects.
To calculate the Defect Tuning Factor, SLIM-Collaborate uses the ratio of total defects found between System Integration and Test and Delivery (normally from about 70-100% of the Phase 3 schedule) to the number of defects SLIM-Collaborate would have predicted based on the system size and total effort. For example, if one of your completed projects reported 750 defects and SLIM-Collaborate would have predicted 500 defects, the Defect Tuning Factor would be 750/500, or 150%.
If you have no historical defect data, use the default QSM Defect Tuning Factor of 100%. The reliability algorithm was derived from studying defect data from the QSM database. It allows you to produce data-driven reliability estimates until you can collect your own historical data and tune reliability estimates to your quality standards and reporting.