Retrieving value
February 1st 2008

The principles of lean production are being applied to all areas of manufacturing and warehousing operations. The storage and retrieval of small parts is no exception. Richard Price, business development manager at Kardex, explains how stores are becoming leaner

It is difficult to have anything to do with modern manufacturing without coming into contact with the philosophy of lean manufacturing. The basic ideas of singlepiece flow, continuous improvement and the relentless elimination of waste that have helped shape today's industrial powerhouses, are being used to some degree by every manufacturer interested in remaining competitive. These fundamental principles are an enlightening tool when evaluating options for parts storage too.

Modern automated storage and handling systems dramatically increase the storage density of small parts. These systems – exemplified by the Kardex Shuttle lift-based units and Industriever vertical carousel systems – deliver their contents quickly and accurately direct to the operator. They also integrate seamlessly with inventory management and manufacturing execution systems to provide accurate information flows right across the business. Together, these benefits can be applied to all the Seven Wastes that lean manufacturing efforts seek to target.

In traditional manual storage systems operators can travel tens of kilometres every day in the process of picking and storing items. The goods-to-man principle that underlies all automated storage and retrieval systems is one of the biggest productivity gains from this technology, saving time, improving ergonomics and allowing workers to operate in well laid out, comfortable workspaces.

To ensure inventory accuracy in manual storage systems, parts may have to be scanned or manually keyed into multiple inventory management systems several times during delivery, storage and retrieval.

Automated handling systems with full software integration reduce unnecessary processing by seamlessly allocating appropriate storage positions for incoming stock as it is manufactured or delivered.

Incoming material can then simply be scanned into these spaces, with any mismatches automatically detected and flagged.

Speed and accuracy Any time that a worker spends waiting is time lost and money wasted. As a result it is important for storage solutions that feed manufacturing processes to get the right parts to the line on time, every time. The speed and accuracy of an automated system delivers clear benefits here.

For warehousing and distribution operations, waiting can be reduced by taking previously sequential operations and making them parallel. Using linked sets of automated shuttles or carousels, for example, operated with the latest generation of sequencing and control software, such as the Kardex PowerPick 5000 suite, allows machines to automatically pre-select the next item in a pick list while the operator is still picking the previous one.

Picking productivity can be improved up to 8-fold using this approach.

The high storage density provided by automated units also allows work-inprogress, components and consumables to be stored much closer to the production line, so less time is spent moving components about needlessly.

Picking errors that result in the wrong product being shipped to a customer or being incorporated into the production process waste time and money. Automated storage and retrieval systems provide a significant improvement in picking accuracy by offering only the correct products to the operator. The basic Shuttle and Industriever systems are equipped with pick-to-light systems which indicate the exact storage location for even higher accuracy. For the very highest levels of picking accuracy secure systems, like the Kardex Sentinel, physically restrict access to all but the required product. This system provides perfect 'poka yoke' – mistake proofing – during picking and also improves security for high value parts using a similar concept to vending machines.

The final two wastes – unnecessary inventory and overproduction – might seem to be outside the scope of storage technology, but today's systems can help here too. The visibility of inventory provided by integrated, automated retrieval systems is much higher than that offered in any manual storage technique. This means that 'safety factors' built into inventory plans to cover inaccuracy and loss can be reduced or eliminated and production plans can be tied much more closely to real needs, using a digital Kanban approach.

Applied in the right way, automated retrieval systems make the perfect complement to organisation-wide lean manufacturing efforts. By simultaneously freeing up space, increasing productivity and driving down all sources of waste, they provide a powerful, flexible platform upon which to build a sustainable competitive advantage.

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