[vacri]

Speaking of business continuity, staff churn is costly and time consuming - advertising the position, doing interviews, negotiating, paying a recruiter... and even when you finally get the new employee, it takes a few months before they're fully familiar with the job.

It's worth having a talk first to try and fix things, warning the employee that it won't be tolerated again. It's not like once you have the talk you lose all future opportunity to fire them.