can someone describe what it means in chapter 4 "Aviate Complicane"

"Performance measurements will be based on a Participant’s five years of service
immediately prior to transitioning to United, or such shorter period of service as United may
determine in its sole discretion"

If you dont meet some thing(s) in the compliance list, and they see that is was way past you, say 4 years ago instead of 5, and you've improved since then... they can waive it to 4 years instead of 5?