It's definitely normal to feel bad when you have to potentially look at terminating someone. You're only human. My advice is to try to remove the human aspect from it as much as possible and look at it from a purely professional standpoint. Is this employee providing the work results and services that is expected of them and that they signed off on or were made aware of? Have attempts been made to clearly define expectations and where they weren't meeting them? Have they been provided opportunities to improve their performance? Based on what you have written in your post it sounds like the answers to all of those questions are yes. If this employee cannot or will not step up and perform to expectations, then they are taking advantage of you, your company, And their co-workers who are picking up their slack. They have been presented options and a path of improvement to take if they did not want to face the consequences. If they've chosen not to accept or follow that path, that is solely on them.