Sizing · The build-up · Element

The frequency

How often each would buy.

The part

What it is

Purchase frequency separates a one-off market from a recurring one, and the same customer count means very different things in each.

Where the purchase is one-off, replacement cycle is the equivalent figure and is usually longer than assumed.

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.