The Island LOC Index % (ILI) metric is a DETANGLE® Knowledge Distribution metric based on issues selected by the “Features” filter.

The “Features” filter is normally used to select the issue types which capture the functionality (e.g. user stories or features) as “functional” issues of your system in your issue tracker.

The Island LOC Index metric reflects the ratio of LOC of code modules changed by all contributors working on their own on an exclusive set of code modules in relation to the LOC of all changed code modules when implementing primary “Feature” issues. The code modules behind make up knowledge islands.

The Island LOC Index must not be too high and not too low, since:

• a high value indicates many code modules representing knowledge islands and thus knowledge risks,
• a low value reveals a suboptimal split of work on the respective code parts and
• a medium value represents an optimum of parallel work going on

Therefore,  icons in the DETANGLE® diagrams on ILI are used for the following to thresholds:

• 👎 more than 60% of the LOC of changed code modules count up to the current ILI value in the last time period.
• ⚠️less than 60% but more than 40% of the LOC of changed code modules count up to the current ILI in the last time period.
• 👍 less than 40% of the LOC of changed code modules count up to the current BFI value in the last time period.

ILI is calculated along the code structure of the code base, for files, folders, the whole system and for each time period:

Take a look at DETANGLE® Metrics at a Glance for an overview of all metrics.