Come on A she, we all know what high performance grades requirements are. You have seen these people around you.
I have spent 5 of the last 7 years receiving them, with the remaining 2 years being where I got promotions (££££s) halfway through the year, hence a normal grade at the end...
You volunteer for the toughest projects, the real painful horrible things which are in trouble for whatever reason and you fix them faster and better than expected. You don't show off or shout about it, just do it, suck it up and slap a smile on even if you hated it (which I have many a time, cleaning up other people's mess).
You work harder than the others. That doesn't mean you just sit in the office for the sake of it (I hate that and even enjoy a bit of working from home sometimes), I mean you take on a fair few extras, things that genuinely help your Programme Director - Managing Principle or whatever they call it at your place.
Most importantly, you show passion, you genuinely care for whatever you are doing and the people you line manage.
Voila, watch the bonus money and higher raises come in. Easy Peasy. Ish. Tiring after 7 years. But I'm a newbie from Industry just in, so no doubt politics / who you know etc plays a bigger part on your end grade? Others will be better at answering that.