Perpetual motion machine

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by Emily Atkins
DSV’s Rob Chanona (L) and SSI Schaefer’s Saif Sabti.

The motion never stops at DSV Solutions Canada’s Brampton, Ontario, distribution centre. Human order pickers are a blur of movement, some of them using a foot-powered scooter to whizz around the aisles. On the periphery AGVs stop and start, waiting to deliver bins of product to an overheard conveyor system that looks – at first glance – like the automated racking at the dry cleaner. It’s in constant action as well, delivering pouches of product to the final packing stations.

This perpetual-motion machine is the product of a 25-month project for the third-party logistics provider. Two years ago DSV Solutions Canada was facing explosive growth in a large client’s fast-moving consumer goods e-commerce business. To handle the increased volume at its Brampton, Ontario distribution centre the 3PL was bringing in extra, temporary labour, and experiencing human traffic jams in the picking aisles.

And it was obvious the challenge was only going to grow. Rob Chanona, managing director for DSV Solutions, Canada, takes up the story: “We did a volume projection, five years out, and realized that in this facility we wouldn’t have the capacity to house the number of employees needed to keep up with the orders.”

DSV analyzed transaction and WMS data along with projections from its client, and figured out that the best solution would be to add technology at the existing site. Moving to a larger facility was not an option, Chanona said, because it would not have been a cost-effective move.

Weasels in waiting. The AGVs carry totes of batch-picked product from the pickers to the induction stations.

Analysis and creativity

Once this was decided, the search for a solution partner led the DSV team to SSI Schaefer. “SSI Schaefer was one of several that we looked at. And in the sales process, they convinced us they were the subject matter experts and they truly understood our needs as they understood where the market was going,” Chanona said.

SSI Schaefer brought an engineering perspective to the table, said Saif Sabti, vice-president sales and operations and managing director for SSI Schaefer Canada. Using the combined expertise of the local team and DSV’s global engineering team, they “really looked at different processes as well as different solutions,” he noted.

They needed to work within the existing footprint and allow for continuing growth, while also being able to complete the installation without disrupting operations. As well, the system needed to be able to adapt should the client or its needs change. To meet these challenges they considered a number of options including using an automated storage and retrieval system (AS/RS), put walls or a conveyor system. “As with many of these systems, the challenge is that there are lots of different ways you can solve the logistical problem,” Sabti said.

Weasels in motion

Ultimately SSI Schaefer proposed using its Weasel AGVs combined with an overhead SSI Carrier pouch system. Twenty Weasel AGVs, which run on lines on the DC floor, autonomously convey batch-picked orders to five induction stations. There the items are scanned by an operator and placed into a pouch, which hangs from the overhead carrier system. The pouch carrier system then sorts the items from the batches into orders and sends them to one of 29 pack-out stations where the orders are packaged, sample products added, and the orders are completed.

Workers process orders into the overhead sorter bags at these induction stations.

Continuous operation

One of the requirements of the installation was being able to operate the facility without interruption. This was complicated by the client’s seasonal operational requirements, and by the fact the DC required some renovation to accommodate the SSI Schaefer automation.

“One of the challenges was to work around certain blackout periods (promotional peaks) in the year and we couldn’t do anything during those periods,” Chanona said. “We were ready to go earlier, but we needed sufficient runway to safely commission it.”

As well, some racking had to be removed and some repurposed to make space for the sorter. A mezzanine had been installed when the DC ran out of storage capacity. It was redeployed for the pack-out stations.

There were numerous considerations in the renovation process. The installation team had to work around the existing racking and the mezzanine and make sure the loads were appropriate for the mezzanine when mounting equipment. “Of course we also had to address the safety aspect of moving large pieces of steel and racking and mezzanines while operators were fully picking,” Sabti noted.

“That was an amazing aspect of this project,” Chanona said. “I give a lot of credit to the DSV employees for their flexibility and their ability to respond to constant changes. At one point we had the receiving in one area of the warehouse and then a month later the receiving was in another area of the warehouse as the construction went on.”

Once the technology was in place DSV also needed a seamless transition for the staff in order to maintain continuous operations. To help facilitate the changeover, everyone had a two-hour classroom session and was able to take part in mock-up demos. “It went relatively easily when it came time to do it live, because they had the training,” Chanona explained.

“As we moved from manual to automation, nobody wants to look back at the manual process; everybody prefers the new system.”

It also helped that SSI Schaefer had set up a demo Weasel loop so employees could see how it operated. They were able “to become familiar with and learn to work in conjunction with an automated system,” Sabti said.

“It was also creating buzz and excitement about automation. We were part of the big intro and I was sensing people were excited.”

A Weasel is lined up at the induction station, ready for the worker to remove items and scan them. When they are done they hit a button and the Weasel returns to work.


While the installation went smoothly, the team did raise a question in the planning phase about how the pouches would handle delicate items being fulfilled.

“One of the initial concerns we had was potential product damage, because the pouches in the matrix sorter could hit another pouch,” Chanona said. So they went to SSI Schaefer’s European validation centre for the pouch sorter and inducted 24 champagne glasses. “If it didn’t break the champagne glass, we knew we’re okay. And it didn’t.”

With automation comes a high requirement for electrical power. Upgrading the backup systems was a key part of the installation as even the slightest interruption in power means a time-consuming re-start procedure. “We actually ran a few tests together to see the impact of completely losing power and the time it takes to recover to fully operational,” Sabti said.

The study determined that installing a universal power supply was the best option. “We’ve got a UPS out there that’s probably the size of a small pickup truck,” Chanona added, “but we simulated a shutdown and it works.”

Another side-effect of the automation has been a change in the way operations are supervised. Chanona notes that with the speed of the system it was quickly apparent that they needed someone to coordinate between the human and machine components. So they hired a control tower specialist, Daniel Erwin, who works with the warehouse supervisors to level out the workload.

“In order to maximize the output and the efficiency of the sorter it is crucial that we always have a balanced workload throughout the day. The control tower position is key to maintaining the proper buffer size on any given day; which allows for an even flow of work from start to end. We needed individuals that had mechanization, automation experience. It’s definitely become a key role for us,” Chanona said.

Fulfillment process

In the old system orders were picked individually to carts loaded with 40 cartons. Pickers would roam the aisles collecting each order and then deliver them to the packing stations.

Now orders are batched, and allocated using dynamic zones. Pickers put all the items from a batch together in a single tote and then move the tote to a Weasel AGV. It runs the totes around the perimeter of the racking to one of the five induction stations.

There a human worker scans each item and places it into its own pouch. As soon as the pouch senses there is an item onboard it moves off into the matrix – as the array of hanging pouches is called – waiting to be grouped together with the other items in its order.

“So they’re constantly inducting, and a new pouch is presented in less than a second,” Sabti said. “The operator is presented a pouch automatically, the item is inducted, then it goes into a pouch buffer waiting for sortation. From the induction point onwards, it’s fully automated until the pack-out stations. The buffering process, using goods-on-hanger conveyor lines, is installed on the mezzanine to utilize vertical space. After that, the pouches are sorted and drop in sequence into the pack-out station.”

The system drops one order at a time, so packers know to scan the items and put them in a box. The receipt prints out the packing list, it goes in the shipping label and the box gets pushed onto a conveyor and eventually onto to a truck.

Chanona explained that the pouch sorter is essentially a virtual put wall: “The orders are sent off randomly, the machine actually does the matrix calculations and brings it out at the end fully lined up to the e-comm order.

Efficiencies gained

With the pouches capable of moving though induction at a pace of one per second, this system flies. The sorter can handle more than 6,500 pieces per hour, and the batch picking system significantly increases individual productivity rates.

As advertised, it has also alleviated traffic in the aisles. “It has reduced the congestion in the warehouse,” Chanona said. With the old system all the high-velocity items were traditionally organized in one area, which caused traffic problems, especially with promotional periods when orders could jump 100 per cent overnight. “It became more and more obvious as we neared the end of the two year implementation that we were on the right track,” he added.

For this particular customer DSV and SSI Schaefer designed a unique induction process for sample products that customers can request with their orders. Because these items are not barcoded they cannot be included in the main batch picking process. “Because it’s not in inventory, it’s very difficult to match to the orders that are picked from inventory,” said Chanona.

So the system was designed to induct the samples separately then match them with the right order in the matrix sorter. It gets even more complex, however, Sabti noted, as sample inventory is not guaranteed, meaning there are sometimes substitutions, and that also has to be accounted for in the induction process. But by the time the order gets to the pack-out station its seamless. “It’s just one more item an operator has to pick from the pouches,” he said.

Fast tech

The pace of the client’s online orders, as well as the ability of the SSI Schaefer system and the human workers to keep up with demand, together dictate the speed of operations at the DC. And the people working there have a special tool to help them keep up.

Called ‘mouse carts’ these are human-powered scooters attached to picking carts that some staff use to navigate the aisles. Capable of carrying multiple totes, they are fast, fun and dramatically reduce the number of steps the user must take to fulfill a batch. These were the brainchild of DSV Canada’s senior manager of engineering, Burak Balki, who saw them in action during a site visit to another company’s DC.

Chanona said at first they expected to have to teach staff to use the mouse carts. But instead they had to make people wait until construction was done. “We had to actually rope them off so people wouldn’t start using them,” he said.

Now, to facilitate their speed of movement the DC is equipped with one-way aisles and, like any safe material handling equipment, they have bells to warn they are coming and a braking system.

The carts are a low-tech solution juxtaposed against the stunningly advanced SSI Schaefer automation. But the two work seamlessly together.
“We’ve added a very high-tech system, but we haven’t ignored that sometimes low tech gives us some benefits as well,” Chanona concluded.