This is very true in corporate America. They are NOT really interested in improving your work performance. They are simply starting the process of letting you go while building up the necessary paper trail to show employment lawyers (in case they show up) that the management did their best to try to help the employee improve performance but that it just didn't work out. They are just covering their butts.

So if you ever get called in for performance improvement meeting by your manager, you should just start looking for a new job. Or at least start saving your money for unemployment.

And as for the original poster, I'm sorry that it happened but he should've been up front about his schedule so that his managers know what's going on.