The mechanism · The earning · Element
The tiers
Whether earning varies by status.
The part
What it is
Tiers create a target to reach and a status to lose, both of which change behaviour more than the earning rate does.
They also create a group who will not reach the next tier and for whom the programme has stopped motivating anything.
The smallest level
The attributes it carries
Each attribute is one of the framework’s shared types. What a date is, and how it is written, is defined once for the whole model — the note here says what it means in this particular place.