Work in process, or WIP, is inevitable in most manufacturing processes. It often clutters the production floor. And keeping track of WIP can be haphazard at best, impossible at worst at many plants.

But that's not the case at NTN Driveshaft in its Columbus, Ind. plant. The facility makes good use of automated storage buffers for WIP throughout NTN's manufacturing process of building constant velocity, or CV, joints for front-wheel and four-wheel drive vehicles.

These buffers are automated storage and retrieval systems, or AS/RS units. They provide accurate, real-time inventory control. That enables NTN to maintain strict first in/first out, or FIFO, lot tracking for better quality.

What's more, by taking WIP off the floor, these buffers have not only cleaned up the plant, they have freed up valuable floor space for production.

As a result, NTN has doubled its production capacity. The automated buffers also help ensure reliable, on-time shipments to NTN's customers, most of which use just-in-time (JIT) manufacturing processes.

Driveshaft production at NTN includes forging, turning, heat treatment, grinding, and assembly steps. Unit load AS/RS systems throughout the plant store WIP between these steps. These buffers also hold finished goods waiting for JIT shipments.

Unit load AS/RSs at NTN are one-, two-, or three-aisle systems. Finished driveshaft assemblies, for example, go into a three-aisle AS/RS, which has input/output stations at either end of the system. This system buffers these finished items until needed for JIT shipments to auto assembly lines.

Real-time software tracks lots throughout the manufacturing process with the FIFO control that NTN's customers require. Workers also don't waste time searching the production floor searching for parts and materials with this tracking capability.

The compact, unit load AS/RS units provide high-density storage in a compact footprint. Areas previously used to store WIP are now used for production, helping NTN double its production capacity.

"With this system, we've had an opportunity to actually expand based on increased storage capacity," says Jim Miracle, assistant manager for production control.

Eskay, a Daifuku company
800-253-1003
www.eskay.com