Deliverability · The breaking point · Element
The headroom
How much margin remains before the promise breaks.
The part
What it is
Expressed as the distance between current load and the point of failure — how much more volume, how much less staffing.
Headroom shrinking over several periods is an early warning that is available long before the first failure and almost never watched.
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.