Slippage · The usual suspects · Element
The unfixable
Which have to be lived with.
The part
What it is
Regulatory timelines, third-party lead times and seasonal availability. These are what buffers are actually for.
Treating an unfixable source as a performance problem produces pressure and no improvement.
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.