I was a manager in software development for a GE subsidiary during the Jack Welch era. I was very impressed by the way Human Resources operated. It did an excellent job representing the interests of employees. Within GE, a company head of HR directly reported up the line through the GE HR structure and only had a dotted line to the local CEO.
I personally witnessed 2 instances of how the system worked when a manager's direct reports lost confidence in him/her. I both cases, the manager was placed on probation with a plan to fix the problems. Performance to the plan was monitored by HR and if the manager failed to remedy the problems he/she was let go. We all knew we could take management issues to HR for a fair and confidential hearing. I haven't seen that effective a system since leaving GE.
There were some pretty draconian performance requirements at GE back then. When Welch acquired a company, it had 3 years to become number 1 or 2 in its market segment. If it didn't, it was sold. However, the performance rating quadrants were used only to determine salary increases, not to mandate firings. I managed a high-performing group with no slackers. I was always able to get my people fair salary increases (but I did have to go to bat for them and justify the increases). I’m sure that within GE in that era, there were managers who followed the letter of the law and not its spirit, but the intent was always the carrot and not the stick.