Churn

Description

Development teams change software to add features, to correct defects, and to refine software performance according to variety of non-functional requirements. Changes to software can introduce defects, and so measuring change is important for assessing software quality. We measure Churn, the number of non-blank, non-comment lines changed, added, or deleted in the the software being working on, over a time period. Churn is composed of three measurements; Start Date, End Date, and the total changed, added, deleted SLOC between the Start Date and the End Date.

Data Collection

Select the Start Date and End Date to be measured. In our initial studies, we define Project Month, and compute Churn for each month since the first available month of data for the project, using the first and last days of each month as our Start and End Dates. In other studies, Start and End Dates may be for a single release, or series of releases.

Following the data collection procedures for SLOC, measure SLOC for the Start Date. Measure changed, added, deleted SLOC for the End Date, relative to the Start Date.