Within a small footprint, a tote (or cartons) dedicated to a single order requiring multiple items (eaches) can be sorted to both sides of the lineshaft conveyor every 50 to 100 degrees. This allows an operator to pick individual items from carton flow racks located in their area, place those items into the tote, and then put the tote back on the conveyor so it can be sorted directly to the next picking zone. This setup significantly reduces order fulfillment time and labor costs, since pickers only need to concentrate on their smaller zone. The pickers become very familiar with where each item is specifically located in the rack and they don’t need to walk long distances.
Once the tote is automatically sorted to the next zone, another picker is waiting to add more items to the tote. This continues until the order is complete and the tote is conveyed out of the carton flow area for packaging or shipment.
2. Pusher And Swing-Arm Sorters (rate range: 0 to 20 PPM targeted range)
Pusher and Swing-arm sorters have a low initial cost but are quickly becoming obsolete technology, or only used in unique situations due the potential for product damage, high noise, low throughput rates and large required footprints or gaps between products.
Sortation And The Role Of RFID
Advances in sortation, such as the arrival of RFID barcoding, have significantly changed the sorting landscape. Distribution centers can now, with 99.5 percent accuracy, establish the number of products in the warehouse, their specific location, where they are to be moved and where they are to be shipped.
Bar codes interface with a WMS to act like a traffic cop to track the movement of all items. The manual inventory tracking of the products is no longer necessary, eliminating not only human error but the need for “human touch” to move product from Point A to Point B. Along with giving more accurate counts, the RFID can help increase speed and productivity.
However, the additional cost to implement an RFID system—a label with a radio chip is used instead of a traditional barcode—many DC operations are still in the “discussion” phase. As the cost-verses-benefits gap continues to narrow slowly, an RFID system that can track an item from inception through manufacturing will become more of a necessity. The medical device and prescription drug industry will most likely be the first to implement RFID systems, where both speed and accuracy are required.
The value of a sortation system was best expressed by a facility manager who pointed out, “In the time it takes a human being to read a label on a single carton and determine where it needs to go, a high-speed sorter can read and act upon upwards of hundreds of cartons.” And when a DC is handling over a million units per week, that increase in throughput translates into a boost in productivity that’s difficult to ignore. Evaluating your company’s situation regarding your storage requirements, shipping specifications, and most importantly, your future goals, provides a helpful analysis to determine if an automated sortation system is right for you.
Note: All sorter rates specified are a conservative rule-of-thumb that can be achieved for nearly all applications. Although higher rates may be obtainable, the specific application, product sizes, product type, type of induction system and scanner technology will dictate the maximum rate. So please practice due diligence and realize that sales and marketing literature will typically publish maximum rates which are only achievable under a perfect scenario.