Tim Tetzlaff is the global head of digital transformation at DHL Supply Chain. In that role, he considers various technologies the logistics provider might adopt or develop to improve operations, such as case unloading systems.
Tetzlaff said part of his job is to “make sure we don’t do things randomly, but look into where we’re not using human labor to maximum effectiveness.” DHL Supply Chain has more than 2,000 operations and 188,000 employees worldwide.
“To focus our innovation efforts on the most impactful areas, we make use of data on our labor spend,” noted Tetzlaff. That is, the company figures out how much of its human workforce is spent on each step of the logistics process. DHL discovered that unloading accounts for more than 10% of its labor, and the process was thus flagged as a key area for innovation.
Also, employees don’t typically enjoy the task because “unloading is physically demanding. And it can be very hot or cold in that container,” Tetzlaff said. Not only did case-unloading robots have significant potential to improve overall efficiency, but they could also help DHL retain employees.
“No robots existed on the market that could perform that task with the level of flexibility we wanted,” Tetzlaff recalled.
So, DHL partnered with Boston Dynamics in 2018 to develop a case-unloading robot. That resulted in the Stretch robot. As of June 2025, DHL has deployed 10 Stretch robots deployed for case unloading across three countries, and it plans to double that number by the end of the year.
Robots offer advantages over manual unloading
Stretch can unload 700 cases per hour. Although a human may be faster for the first hour, Tetzlaff explained, “humans can’t work continuously like a robot. Even after two hours, a human can’t maintain the same rate.”
Boston Dynamics designed the robot to be easy to operate. “One of its advantage is that a massive amount of training isn’t needed,” said Tetzlaff. “It gives us more flexibility [if more people can use it].”
After a trailer backs up and a dock door is opened, warehouse staffers use an iPad to move the robot from its charging base to the door.
“It has vision technology so it can autonomously unload cartons from the trailer and put them on a conveyor belt,” Tetzlaff noted.
In its use of robotics, flexibility is a priority for DHL, as is safety, he added.
“At the moment, we do have a light fence around the robot, so humans aren’t too close while it’s operating,” Tetzlaff said. “But we’re working with Boston Dynamics on new features. Could it just have a geo-fence, for example? Can we use other technologies to make that infrastructure as unintrusive as possible, while ensuring we never compromise on safety? As we continue to develop the robot, we expect it to get even more flexible.”
How does the DHL collaboration work?
After initial proof of concept and research, the first trials were in Boston Dynamics’ lab with the robot manipulating standardized boxes.
“In the lab, you get to have perfectly sized shoe cartons with perfect cardboard and perfect tape. That’s not reality,” Tetzlaff acknowledged. “So we shipped them examples of product that we might really get — boxes that are wet, dented, or the tape is coming off. This helped them develop the smart gripper on the robot arm.”
Once the robot was developed in the lab, then Boston Dynamics worked in DHL’s facilities so the robot could face further trials in a controlled, live operation. Then it was scaled across multiple operations. Scaling is critical. As Tetzlaff put it, “Innovation is only real when it’s scaled. Otherwise, it’s just a nice idea.”
“We plan a significant acceleration of deployment towards 2030, as we unlock the new use cases of case picking and more complex freight unloading,” he said, referring to DHL’s plan to acquire more than 1,000 Stretch robots by then.
How Boston Dynamics’ Stretch manipulates boxes
The arm on each Stretch unloading robot is equipped with a smart gripper, which uses suction cups to pick up boxes.
“Stretch uses artificial intelligence and computer vision to continuously increase the range of cases it can handle,” Tetzlaff said. “We’ve already seen a significant increase in its ability to handle different types of cases.”
If the robot identifies a carton it can’t handle — such as if a box has come open on the top, or the tape is missing — the system will inform an associate to intervene and resolve the issue, he added.
However, If a box falls on the floor, the system can still identify it as a box and pick it up from the floor, just like usual, said Tetzlaff. Stretch can then put it on the conveyor belt.
The robot is currently limited in the types of products it can unload.
“We recognize that Stretch is not ready to unload all containers, such as one full of canoes or ironing boards,” Tetzlaff said. “But we hope there will be more types of products that it can handle over time.”
Along with developing greater flexibility in the type of product Stretch can handle. Boston Dynamics also plans to increase flexibility in the types of tasks it can perform.
Partners move from case unloading to case picking
DHL plans to continue co-developing Stretch with Boston Dynamics. Given the aim of greater flexibility with the same robot, the next major task DHL wants Stretch to tackle is case picking.
“Globally, case picking is 15% of the human labor we spend. So we have an even larger opportunity for deploying this type of technology,” Tetzlaff said.
Case picking is no simple task. Once human employees know what needs to go onto a pallet, they find out where the products are located in the warehouse, locate them on the shelves, and load them onto pallets in a sensible order and a safe, stable pattern.
“Stretch doesn’t require a whole lot of navigation for unloading. You just steer it to the container, and then it’s the arm doing the work,” Tetzlaff said. “But for picking, the robot has to drive through the aisles, stop at the right points, identify the right products, pick up the cases, and stack them properly on a pallet.”
For example, for Walmart, DHL might have to put three heavy cases on a pallet with five light and fragile cases. It would be bad if the robot put cases of laundry detergent on top of cases of chips!
The goal is to integrate Stretch with technology DHL already uses, and to add new software as needed.
“We already run best-in-class operational IT systems, such as our warehouse management systems [WMS],” said Tetzlaff. “Suppose we introduce a flexible robot like Stretch, which takes on both case unloading and case picking tasks. We’d connect Stretch to our WMS so it can receive orders to be picked, locations it has to travel to, and so on.”
DHL could also add software to continuously optimize the path Stretch takes through our warehouse. For instance, such software could tell the robot to avoid blocked aisles and busy areas, Tetzlaff said.
He said DHL Supply Chain aspires to provide contract logistics services that are digital by default. “This means we operate supply chains where technology, people, and data work together seamlessly and resiliently,” said Tetzlaff. “We are the best integrator to bring all these assets together.”
About the author
Zena Ryder is a freelance writer based in Canada. She specializes in writing about robotics and construction for magazines, websites, and businesses. Ryder also ghost writes nonfiction books. She can be reached at her website or on LinkedIn.
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