I've experience this before, and I'm experiencing it again now, and it's causing me to go a bit crazy because the work I do is very much dependent on teamwork. It requires two bodies. One person cannot do it alone. Despite the work being quite simple, straightforward, and semi-repetitive (same process every time), the person I work with cannot do it right with any amount of consistency. Not only that, but she often does bizarre things that make no sense whatsoever, and when she's asked why she did X, she gets a blank look on her face and says, "I don't know." Pushing things even further, she thinks she knows better than everyone else and will often jump in the middle of things when she shouldn't and screw everything up. It's usually just annoying, but sometimes it actually messes up our work.
I am kind of at a loss as to what to do because she's worked there almost 10 years, and our boss is not on site. I've thought about keeping a log book, but I'm not sure that would really do any good either.
Anyone been in a situation like this? What is your advice?