Do you have probation period where you work? i.e. if an employee doesn't live up to expectation, release with short notice? Where I am, a 3 year contract typically carries a 3 month probation period, and a 1 year contract carries a 1 month probation period.

The problem is management are often too busy or overwhelmed with other stuff to observe and provide feedback until someone's passed the probation period then releasing them becomes a bureaucratic nightmare - and when the new hire's not getting feedback, you can be sure not a lot of the rest of the team are.