Inventory · The reorder rules · Element

The safety stock

The buffer held, derived from variability and service level.

The part

What it is

Demand variability and lead-time variability compound. Both are needed, and lead-time variability is the one usually omitted.

Recomputing periodically matters, since demand patterns shift and safety stock set three years ago protects against a former business.

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.