Lead time is the lag between ordering something and being able to use it — from the moment you hit "buy" with a supplier to the day the box is on your bench. It bundles the supplier's processing time and shipping transit, and for custom or imported materials it can stretch from days into weeks.
Lead time is the hidden driver behind reorder points. The longer it takes to resupply, the earlier you have to reorder, because you must carry enough stock to keep producing through the entire wait. Underestimate it and you stock out mid-production; overestimate it and you tie up cash in inventory you did not need yet.
Lead times also fluctuate — holidays, supplier backorders, and seasonal demand all stretch them — which is exactly why a safety-stock cushion sits on top of the usage-times-lead-time calculation.
Related terms
Par Level (Reorder Point)
The minimum stock level at which you place a new order — set so replenishment arrives before you run out, without sitting on months of excess.
Safety Stock
A buffer quantity held above the reorder point to absorb unexpected demand spikes or supplier delays without causing a stockout.
Ingredient
A raw material or component purchased from vendors and used in recipes to produce finished goods. Examples: flour, beads, essential oils, fabric.