Inventory Is Available Only When Production Can Use It

Inventory recorded in the system is not the same as usable material at the point of need. Production availability depends on the correct part, quantity, condition, location, and timing.

Trace the apparent contradiction

When the system shows stock but the line reports a shortage, follow the specific item. Check receiving status, quality holds, alternate locations, units of measure, allocations, and recent movements.

Avoid accepting “inventory error” as the final cause. Ask what transaction or physical handoff produced the difference. Otherwise, the next count may correct the balance while leaving the failure mechanism intact.

Separate the types of availability

Distinguish physically present stock, unrestricted stock, allocated stock, and material actually presented for use. Make sure planners and operators understand which condition a report describes.

In a hypothetical scenario, components may be in a warehouse reserve location while the forward pick location is empty. Purchasing more does not solve the immediate internal replenishment problem. The required action is different from a genuine supplier shortage.

Make ownership follow the material

Define who owns each transition: receipt, inspection release, putaway, replenishment, picking, and point-of-use acceptance. Identify the record or signal that confirms a successful handoff.

Check the exception route. Material placed temporarily in an unrecorded location can become invisible to the next shift. A designated exception area with controlled status is more useful than informal knowledge about where someone left the parts.

Measure the operational experience

Track shortages by cause and the time required to restore usable supply. Compare system accuracy with point-of-use availability. Both matter, but they expose different problems.

Observe a full replenishment cycle with planning, warehouse, and production representatives. The conversation often reveals assumptions that each function considers obvious. Turning those assumptions into shared operating rules is a practical first improvement.

Continue reading: Kanban Container Quantities: Check the Assumptions Before the Math.