Batch buffers and matrix sortation

What do these terms mean and how do they work in pouch sorter technology?

The e-commerce revolution continues apace and the retail industry is still having to contend with ever-increasing service level requirements, unpredictable delivery demands, mounting order volumes, variation in items and the nightmare of handling returns. In the fashion industry in particular, as e-commerce sales become more prevalent, omnichannel operations - supporting both retail and e-commerce - are now inevitable for fashion logistics companies.

So what's the solution? "With pouch system technology, fashion fulfilment businesses can improve their omnichannel order fulfilment capabilities and meet the demand to handle both B2B and B2C," says Harald Hanaweg, head of sales engineering at BEUMER Group. Pouch sorter technology is a flexible unit sortation solution that is gaining increasing popularity in the apparel industry for its ability to deal with omnichannel order fulfilment.

It is essentially an overhead sortation system that relies on pockets, pouches, or bags to store and convey products. "A pouch sorter system has the ability to simplify and streamline a number of process steps in omnichannel e-commerce fulfilment," continues Hanaweg. "It can support efficient picking, the smart handling of returned items and the processing of different order lead-time requirements easily - all important factors in omnichannel fulfilment." Batch picking can be applied to any kind of sorting technology, including loop sorters, but here the batch size - or number of orders handled - is limited to the batch capacity of the sortation system.

In a pouch sorting system the only limit is the number of items the buffer can hold. Hanaweg explains further how this works. "The items retrieved from picking are inducted to the sortation system, where they are held in a batch buffer until all the items have been gathered, with one item in each pouch. The circular batch lines typically hold two picking batches, each consisting of a mixture of orders.

The system confirms that all items in the batch are present in the buffer where they stay until they are needed, before the items are then sent through the algorithm-based matrix sortation." One of the limitations of a loop sortation system, for example, is that a batch of orders can be built only after the items are discharged into compartments inside the destination chutes. But in the pouch system, because orders are placed into the dynamic batch buffer first, orders within a picking batch can also be prioritised, for example according to cut-off times.

What's more, the buffer is overhead and so does not take up space on the floor. A further refinement of a pouch system is its matrix sortation capability - a feature not found in other sortation systems. This uses a sorting algorithm whose parameters are set by the pouch system supplier.

For example, BEUMER Group's algorithm sorts six lanes of pouches three times. In other words, 6x6x6 or a total of 216 pouches/items are sorted in one rotation batch. "The matrix sortation basically means that items enter the buffer in no particular order and exit in perfect order," enthuses Hanaweg. "The beauty of the pouch system sorting 216 items into a perfect sequence is that those items can belong to any number of orders," he continues. "This makes the process completely independent from order structure.

It simply doesn't matter if the 216 items belong to 50, 70 or 100 different orders. To the system, the task is always the same - bring 216 items into a desired sequence. This makes the system ideally suited to use in the e-commerce market, where there are typically a large number of small orders."

It is a defining feature of a pouch system that the size of the dynamic buffer limits the size of the picking batch that can be handled, system and warehouse operators should be aware of this in designing a system. "However," Hanaweg concludes, "it is always possible to start with a small buffer and add more capacity later as needed."