Maintenance · The schedule · Element
The spares
The parts required, and whether they are held.
The part
What it is
A cheap part that stops the constraint is expensive to be without, and spares policy should follow consequence rather than part cost.
Long-lead spares for critical assets deserve holding regardless of how rarely they are used.
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.
Lead time
How long to obtain if not held, which is what determines the holding decision.
Duration shared type