The requirement

What capability is needed, at what depth, by when.

The part

What it is

A requirement stated as a headcount number hides which capability is actually short. Two engineers and two of a specific specialism are different requests with different answers.

Tying each requirement to the plan item that generates it is what allows it to be dropped when that item is dropped.

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.

Capability
Links demand to the map, so supply and demand are read in the same terms.
Reference shared type
Depth needed
Distinguishes needing the capability at all from needing it at scale.
Number shared type
Needed by
The date is what turns a requirement into something with a lead time attached.
Date shared type