Purpose
Duplicated Lines (%) shows a percentage of duplicated lines in the project code compared to a total amount of lines of code (LOC) on the project.
How metric helps
Code duplicates will lead to duplicated bugs and coding standards breaches, etc. Therefore increasing duplicated lines percentage can indicate a lack of good inheritance structure or abstraction.
How it works
Chart Overview
Duplicate code lines are shown in % (Axis Y) and distributed over time (Axis Y) on the chart.
Each project child unit (can be set up in Project Configuration Wizard) in the legend is clickable, and shows/hides its percentage on the chart once clicked. The chart also adjusts a scale automatically to better fit the series shown on a screen.
Calculation Formula
Duplicated Lines (%) = Duplicated Lines / LOC * 100%,
where
Duplicated Lines - a number of duplicates
LOC - number of all code lines
RAG thresholds: Red > 20%, Amber > 5%, otherwise Green.
Data Source
Data for the metric can be collected from Sonar or any other project tracking/engineering tool.