The insight component provides an uptime report for a given system. It reflects the data Leankoala is taking via KoalaPing for a given component.
The insights report refers to a single component as a representative for a given system. This could be the homepage as the most important page for the most web projects. Every time KoalaPing can't reach the component Leankoala considers the page as down, every time it reaches the component (it returns the expected HTTP status code) it considers the page as up.
The percentages Leankoala provides is the uptime ratio.