The economics · The cost · Element

The total

What the programme costs in full.

The part

What it is

Set against the incremental margin it produces, which is the only comparison that answers whether it is worth running.

Recalculated annually, since the economics at launch and at scale differ.

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.