Picking technology
October 1st 2006

Nigel Algar, european sales and marketing director, Warehouse & Distribution Division, FKI Logistex, discusses what to consider when evaluating automation for your warehouse picking and sorting operations

Today's warehouse managers face increasing challenges with customers demanding faster and more accurate order processing, smaller and more frequent deliveries, and senior management calling for lower costs and increased productivity.

Manual picking and sorting remain two of the most labour-intensive, costly jobs providing a major source of errors and inefficiencies. The first place to start evaluating your warehouse for automation is to obtain an accurate picture of your order profiles and volumes.

Turn to an expert You'll also need to evaluate the warehouse layout. Is it conducive to order-picking and sorting techniques and, if so, is it optimal for high-productivity material handling? For an expert opinion, contact a systems integrator, such as FKI Logistex, or a materials handling consultant.

These specialists will analyse your "slotting" – where and how products are stored and their volumes and speeds. This process normally begins with an 'ABC' analysis identifying the fastest moving items (As), intermediate movers (Bs) and the slowest (Cs).

You may find your warehouse requires reconfiguring to optimise product storage prior to picking, sorting and, ultimately, to packing. Also, it may be necessary to rearrange the storage infrastructure.

The goal is to optimise picking, sorting and packing so they make sense within the warehouse space and workforce constraints.

Consider whether poor slotting causes workers to walk too far, bend too much or work inefficiently and inaccurately.

Examine the options A materials handling expert will offer invaluable advice. Do you need conveyors? Is light or voice-directed picking or putting needed? What form of sorting equipment is required – loop or line? Is a sophisticated warehouse management or control system appropriate? Automation could be the right solution. If so, your next step is to determine the level of automation needed.

Initially, the transition from a manual system to an automated one involves moving to radio frequency-based (RF) wireless data technology, supported by RF mobile computers and hand-scanners.

The ABC analysis will evaluate which technology suits your warehouse.

Depending on order volumes, medium and fast-moving items could be candidates for pick-to-light implementation, and possibly put-to-light for replenishment of picked items – replacing paper – based manual systems and increasing productivity by as much as 50%.

Extending a pick or put-to-light system beyond medium and fast-moving items may also be viable. You might decide to implement light technology totally - densely for fast-movers and less densely for slowmoving items. Alternatively, RF-directed carts can be added to a pick-to-light system for cluster-picking slower-moving items.

Voice-directed picking is optional, particularly where RF-based mobile picking hardware is installed. Computer-generated voice commands are particularly suitable for slower-moving items and for warehouses with extra long walks between picking areas.

Voice devices can complement light-based systems, freeing pickers from carrying paper instructions – dramatically improving accuracy and productivity.

High speed sorting While conveyors transport product to the sorter, today's advanced, high-speed sortation systems are truly the heart of most successful DCs. However, with so many options now available, making the right choice is vital and involves talking to a supplier who not only offers a comprehensive range of systems, but also has the resources and expertise to custom design a sorter to meet your requirements.

Whether for item or container sortation, many styles and prices are available. Speeds, throughputs, and costs vary from the lowend sorters using pop-up wheels, to highend sliding shoe (linear) sorters. Handling a few or 300 plus items per minute, sorters use a variety of methods such as tilt-trays, cross-belts, sliding shoe and linear belts. The linear belt sorter uses a series of belt modules to drive products through sortation, allowing it to handle a wide variety of products – from heavy bulk items to CDs.

Loop sorters are more flexible, quieter and faster than line sorters and particularly suited for handling long items, while cross belt systems are ideal for smaller products.

Operating at 144mpm, these discharge in two directions and are suitable for difficult to handle items often found in the textiles, fulfilment, mail order and e-commerce sectors.

The final step Automated technologies require software, and you may need to upgrade your systems to improve order fulfilment. Today's warehouse-specific software is designed to manage picking, sortation and packing as well as optimising throughput by order and wave planning.

The two key reasons to automate are productivity and accuracy. If automation increases picking productivity by 50% and provides close to 100% order accuracy, you're increasing customer satisfaction plus incurring lower costs because you're making fewer mistakes.

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