Ask Lemmy

Broadly speaking (in my personal experience) especially in very large organisations with a union presence employees you usually see salary grades or employee classifications which assign a pay grade. Those jobs in turn come with minimum expectations that you have to meet to fulfil your obligations to collect your base wage.

You can go above and beyond, take on the harder jobs and put your hand up for unpaid positions (union rep, health and safety officer, first aid, fire warden, etc) those roles dont carry a financial benefit and most of the time dont impose a significant time penalty (many workplaces have to accommodate your time away from regular duties) but they are also voluntary.

The thing is, try climbing the ladder internally without taking on any of those roles. They expose you to the inner workings of the business, the metrics, management speak and a measure of exposure to higher management so when an actual position up the ladder does come up anyone else has to compete with the guy who is already on a first name basis with the area manager because of that thing 3 months ago. Someone who has demonstrated that they want it not someone who just applied because there was a vacancy.

People who are non union and free to negotiate their own salary (again, this is just my experience) are often in jobs where the big boss can walk in say "Jim, unfortunately we have to let you go. Heres a glowing letter of recommendation, 6 months salary in leiu of notice and this lovely man from security will be escorting you out in 30 minutes, please pack up your desk.