The threshold

The result at which the decision flips.

The part

What it is

A number or a direction. Where it exists, the analysis only has to establish which side of it the truth lies on, which is frequently much easier than a precise estimate.

Agreed with the decision-maker before the work starts, since agreeing afterwards is negotiation.

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.