- February 24, 2023
- Mobile Industrial Robots (MiR)
- DENSO Robotics
- Case Study
DENSO turned to Mobile Industrial Robots (MiR) to automate material conveyance and is now running six MiR250 robots through two production areas, including transport to and from the warehouse, to support line-side manufacturing, and including facilities and spare parts transport.
Addressing the “last mile” in automation
For many large manufacturers, material conveyance has been the “last mile” for automation. That’s been the case for DENSO, a Tier 1 automotive supplier that manufactures products ranging from spark plugs to fuel injectors in its 800,000-square foot powertrain component production facility in Athens, Tennessee.
“Denso has always been on the forefront of automation and innovation within the manufacturing process,” said Travis Olinger, logistics and automation engineer in DENSO’s Total Industrial Engineering (TIE) group. “But while we’re very automated on our manufacturing lines, we haven’t been as quick to adopt that towards our logistics areas, toward conveyance.” A renewed emphasis on improving manufacturing efficiencies and profitability, combined with a tight labor market, brought automated conveyance to the forefront.
DENSO turned to Mobile Industrial Robots (MiR) to automate material conveyance and is now running six MiR250 robots through two production areas, including transport to and from the warehouse, to support line-side manufacturing, and including facilities and spare parts transport. The company has also purchased five MiR500s for anticipated new business. DENSO is one of MiR’s largest global customers, with MiR robots running in four U.S. locations, three in Europe, and two in Asia.
Need for manufacturing efficiencies drives move to AMRs
Like most manufacturers, DENSO is always looking for opportunities to boost productivity and efficiency. “We knew we had a lot of people that were getting paid to move parts all day long, walking carts from one place to the other,” explains Olinger. “But if we have people that are only conveying parts, then that’s a non-value-added activity, and we had plenty of open jobs for value-added activities within the production environment. We wanted to pay people to make parts for us that makes us money, and not pay them to move parts that cost us money.”
Research showed that DENSO associates were walking up to 12 miles per day moving material between production and the warehouse, spending about 60 percent of their time just pushing carts. “That led us to understand that we had a really big opportunity here for some automation, to take care of that challenge for us,” said project leader Robert Blackburn.
As the team explored options for automated conveyance, it quickly became clear that automated guided vehicles (AGVs) and their infrastructure requirements and costs couldn’t meet DENSO’s needs. Olinger said, “We’re an extremely dynamic environment. We didn’t want to have to go through that entire infrastructure change every time we moved something. The autonomous mobile robot was key to us: to be able to navigate on its own, with quick mapping, quick changes.”
Pilot program for AMRs focuses on warehouse-production conveyance
The team had seen success stories with MiR robots, so they brought both MiR and a couple of other AMR options in-house for testing, using the spark plug production lines as a pilot area. The processes included moving empty totes to production and full finished kit totes back to the warehouse. Blackburn said, “We set up a test course and we ran it [the robot] through the wringer. We were able to throw different things at it, different challenges, and get user feedback. At the end of the day, MiR was the clear choice for us.”
The MiR250 had recently been introduced, and the team was attracted to its two-meters-per-second speed, the payload of 250 kilograms to handle heavy metal parts, and the ability to navigate narrow spaces. MiR as a company also distinguished itself from a business-model standpoint, as Olinger explains. “MiR was prepared to support us, as Denso North America, from the numbers we were going to roll out. We looked at some companies that just didn’t have that same support structure, and didn’t have that history, and we didn’t think that they could keep up. But MiR has been a great partner for us.”
Logistics associate Danny Thompson added, “Honestly, my initial concern was safety. A lot of people were worried about them running into stuff, or hitting something. I was very surprised at how well they responded to anything stopped—traffic or things that have blocked their pathway. The robot’s able to communicate and move out of the way or make adjustments or even come to a complete stop and allow the other foot traffic to continue on. I was really impressed with how responsive they were.”
MiR250 offers significant advantages, including use of REST APIs
The MiR robots bring significant advantages in flexibility, safety, and user-friendliness, and uniquely met other DENSO requirements as well. Olinger said, “MiR stood out from the ability to use REST API calls, the intuitive nature of the Fleet, the ease of mapping, ease of mission creation, ease of changing locations. It was just extremely intuitive compared to the other platforms that we looked at.”
The MiR robots’ ability to use REST API calls were key to the project’s success. “In addition to moving clean, empty totes from our tote-prep logistics area to the production area, and then moving finished goods from production to the warehouse, we also had an information flow we had to replace,” explained Olinger. “We had to know when to come get the totes, and we knew we wanted to use REST API calls for that.”
MiR partner Advanced Control Solutions (ACS) helped develop the third-party integration necessary to work with the REST API calls along with DENSO’s internal software in order to integrate with production. “We use Fleet for our maps for all of our mission creation and our locations,” said Olinger. “But we also wanted to be efficient with some proximity cueing and to allow the associates themselves to call for the robots and prioritize in FIFO [first-in, first-out] order. Also, the REST APIs enabled us to manage charging.” DENSO is able to prioritize robots based on charging status and using a decision tree when a mission is finished. The system looks for other missions available, checks for adequate charge percentage, and sends robots to missions or to charge as appropriate.
DENSO has also been able to integrate the robot to automatically open the door in and out of a clean-room area, using the MiR I/O modules to send wireless signals to WISE Modules in the roll-up door controller. Fleet zones automatically send the appropriate signals via the I/O module when the robot approaches the door.
Associate involvement in planning and cart development are key to success
To prepare for the MiR robot implementation, the TIE team studied the workers in the area to understand exactly what the job entailed, what aspects of the job could be carried out by a robot (conveyance), and what parts of the job would need to remain with the associate. From there, work elements were transferred until all conveyance could be handled by one associate. That person acted as the robot during the research period. “The associate level was very much involved throughout the implementation of the MiR robots,” Blackburn said. “Once we knew that they could handle all the robot elements, we knew that the robot could then take its place, and become that associate. That’s how the transition took place.”
During that time, associates provided invaluable input and feedback to optimize the approach for better efficiencies. Blackburn said, “At the end of the day that’s how you make sure these things are successful. If they have some say or some part in it, they are going to be ten times more likely to go for it, so it’s very important in what we do. That’s how we operate all the time, now.”
Associates are also very involved in the design of top modules for the robots. Olinger said, “As we have designed those cart tops for different areas and different applications, the associates have been instrumental in those design processes because they’re handling those carts every day. We’ve had changes in handlebar design, we have had changes in how they hold parts to match up to whatever they’re unloading the cart to. From an ergonomic standpoint, we don’t just want to replace the conveyance and then shift that work onto someone else. They’re the experts. They’re the people handling the carts, they’re the people handling the parts. They are extremely helpful in those cart designs, and making it a more efficient process.”
Standardizing on the MiR250 shelf-lifter and ROEQ carts allows DENSO to expand quickly into other areas using the same cart base and customizing it for each use. As associates approach the engineering team with requests for automated conveyance, they can easily design racks around the carts, helping to free up space, increase flexibility, and gain the advantages of automated conveyance more quickly.
Those efficiencies now extend to other areas as well. The facilities maintenance crew purchased carts and now gets supplies delivered automatically from receiving. “Our spare parts do the same thing,” said Olinger. “It’s not just components to line-side delivery. Anything that’s getting conveyed we are starting to look at.”
Initial successes lead to just-in-time line-side production delivery and unexpected benefits
After the initial success of the warehouse and spark plug area, Olinger and Blackburn turned to work-in-process (WIP) conveyance and quickly expanded into the gasoline plant. Olinger emphasizes the significant advantages they were able to achieve by replacing information flow in addition to replacing conveyance. He said, “We realized there was an increased accountability factor, and a very large benefit to pulling all of those components back to the warehouse, using a parts ordering system to place those orders, and then replace the entire process. So instead of taking parts up and finding where they go, our associates were then able to get an order from production, kit that order, place it on the robot, and have it just-in-time up to line-side delivery.”
An unexpected benefit was the alleviation of tensions around whether workers had delivered parts correctly, on time, and to the right place. “Now, on both sides, everyone has accountability,” said Olinger. “We know what time parts were ordered, how many were ordered. We know what time it was completed, and when the robot picked it up. It took a lot of that tension away, and allowed departments to work together better, because all the information’s available.”
Immediate and ongoing results with fast ROI
DENSO’s ROI plans for projects are typically less than two years, but the indirect cost reduction specific to the MiR robots replacing conveyance achieved ROI in a year or less. Within six months of the project launch, DENSO was able to cover all finished kit lines in the ignition plant with AMR conveyance and achieve a six head-count reduction in workers manually moving parts. Those workers have moved to inspection processes or other roles that allow them to challenge themselves professionally and add greater value to the company.
As Olinger points out, “From a results standpoint, we’re making quick ROIs based on head-count reduction and eliminating conveyance, but it doesn’t stop there.” Overall employee morale has also improved, with employees recognizing DENSO as an innovative company that wants to make employees’ jobs easier and that the company cares about the ergonomic aspect of the job.
Olinger adds, “We heard an associate earlier say, ‘I don’t have to walk 12 miles a day anymore. I can do something that makes this company money.’ If they’re doing a value-added job every day, and they know they’re increasing the quality or adding to the profit margin of this company, then they’re more bought into the company as an associate.”
Even with some early concerns about the robots from associates, that has changed. During occasional downtime for things like software upgrades, the engineering team hears very quickly from associates: “I’m tired of walking this cart up here. Where’s our robot?”
Olinger explained, “The thing I would say for anyone else that’s looking at potentially rolling out AMRs for conveyance is that the benefits you’re not thinking of now are almost going to outweigh what you are considering. As you start to see the efficiency gains, and how it improves your overall culture, and then how departments will come up with their own ways to use them to save money, there is a broader benefit to be attained than just that initial indirect cost reduction. It’s well worth that initial investment, and well worth that initial period of change. “At this point, we’ve been operating MiR robots since September 2020, we’ve run over a half million successful missions, and they have not called in sick one single day.”
Support and training lead to fast implementation and ongoing success
DENSO received extensive support from both MiR and ACS to ensure a smooth rollout and ongoing success. ACS delivered the robots and walked the DENSO team through the initial setup and mission-creation and mapping process. From there, the robots’ ease-of-use allowed the TIE team to move into new areas very quickly. “Probably a day of setting everything up, and then another week of testing and working out all the little wrinkles,” said Blackburn. “After we learned that first area, we were able to do it independently.”
MiR provided a week of onsite MiR Academy training, including for DENSO employees who could be groomed into super-user roles to support the project long-term. Blackburn explained, “The team leaders and the associates out on the floor are going to be the ones that at the end of the day are responsible for these robots and keeping them in operation. They had the willingness to learn, but it’s also very important that they got leveled-up on more than just the basics, but also some of the more advanced concepts.” MiR has also assigned a Denso North America-specific contact, has created a group for DENSO on the MiR community site, and conducts monthly meetings with Denso.
“The information-sharing has been huge," stated Olinger. “It’s not just a vendor that we’ve bought something from. They have grown with us, they have become a partner, and they are instrumental in how we are now expanding.”
AMRs create a shift in planning and design
DENSO has also purchased five MiR500s for anticipated new business. As Olinger explains, this represents “a major change in how we design lines. It’s in our mindset now that automation and how we deliver components line-side is not a luxury, it’s not a new project; it's just part of the design and how we do things.” With automated conveyance and logistics now at the forefront of production decisions, the TIE team can better plan for things like aisle widths, streamlined processes, and where to focus headcount, with MiR conveyance systems in place out of the gate.
Blackburn stated, “Technology and innovation are very much a part of what we need to focus on going forward. Basically, if you’re not going to focus on that, then you’re doing your company or your plant a disservice by not coming out with the best ways to improve on existing manufacturing environments.”
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