I'm dealing with one of these right now. When I was promoted to my position, I inherited a "worker" who has always been a problem. Her previous manager retired and pulled me aside and said "Keep an eye on Sally, she is trouble. I was always afraid to say anything about it because she has accused me and other of racism if we ever try to correct her." Oh joy.
Year 1, I wrote an honest performance review. Sally does the minimum necessary and take no responsibility for her errors. I spent HOURS if not days fixing her work. Her PR score meant she did not receive a raise. She had a FIT! Even though I was able to show proof of her poor work product, I was "picking on her because she was xxxx! NO ONE had ever told her anything, or taught her how to do her job. Her reviews before I took over were GREAT, so the problem MUST be with me because she did everything she was told."
Year 2, at the beginning of the year I spent a week retraining Sally and providing her with job aids and standards documents. I provided her with feedback throughout the year. Once again at PR time I have to give her low scores. Her work was not meeting standards, she was difficult to work with (I had multiple complaints about attitude, excessive personal calls, refusing to do tasks by others - who were allowed to leverage her as necessary). I had more documentation and once again, no raise. She was given a formal warning to shape up... I spent MORE time retraining her, providing more job aids, etc. she spent her time finding new and clever ways to avoid work and cheat the system.
Year 3 (this year)...another bad PR, the worst yet because her attitude has seriously deteriorated. My boss is sick of it too (she went into MY boss's office and told her that she wasn't managing her staff right!).
We call HR and request to terminate. HR insists we have to give her ANOTHER chance. So, she is now on a formal performance improvement plan. Supposedly, I can fire her if she violates the terms. I'm not holding my breath.
She was out for two weeks over the holiday and we had a temp who was amazing! One hour of training with this temp and she managed to do twice the work with half the errors. It really drilled home that Sally is unwilling or unable to do the work required of her.
My boss says that Sally is the most stubborn, difficult, bully she has ever had to deal with in her 30 years in the work force.
I keep hoping that the failure to receive raises year after year and the increased scrutiny of her work by myself and upper management will drive her out. But, she is like a barnacle, she has worked the system for years, only puts in a minimal effort and gets away with poor behavior without getting fired.