From my own experience, emplacement is dependent on your performance and perm headcount vacancy

For my case, I was emplaced when a perm headcount opened up, which took me 2 years. I was in a way lucky, with my ok performance.

I have another friend who wasn't so lucky. His boss kept avoiding whenever the emplacement topic pop up

In summary, it all boils down to your performance, and how upfront your boss is, with regards to your emplacement probability, because bosses do have their limitations