In open-list voting systems, voters are free to select any candidate they prefer on the party list.
The number of votes each candidate receives determines their rank within the list, and the higher the rank, the more likely to be elected.
So in theory, a political party can end up in an awkward situation where they win a significant number of seats, but their leader manages to not get elected due to insufficient votes. This would potentially trigger a leadership contest and possibly the collapse of the entire party platform.
So how do political parties under this system ensure their leader (and key figures) get into the Parliament?