Award Winners -- TMNA Executive Vice President Chris Reynolds (center wearing white hard hat) presents the Ergo Cup to TMMC team members who brought the frame trolley to life, including (left to right): Nick Phillips, Shawn Duggan, Graham Dowling, Joe Lisk, Ho-Ling Lam, Mike Allard and Dan Scott.
About a year ago, not long after the summer shutdown, several team members at Toyota Motor Manufacturing Canada (TMMC) began to develop discomfort in their left shoulders. No one knew exactly why.
After all, their task — lifting the RAV4’s left-hand door frame, carrying it 10 feet and loading it into a welding jig — complied with the plant’s ergonomic standards. The part in question weighs nearly 16 pounds. Team members are permitted to lift up to 11 pounds per hand. And for this procedure, team members could use both hands.
Why the problem?
“To answer that question, we turned to our team members,” says Ryan Westbrook, assistant general manager of Stamping and Body Weld in the Woodstock, Ontario facility.
Team Members Dig In
Specifically, Graham Dowling, production group leader of the Shell Body Line, formed a cross-functional quality circle of team members representing production, maintenance and engineering to try to unravel this mystery.
Eventually, they identified the root cause: Due to the shape and size of the door frame, team members were supporting most of its weight in their left hand while using their right hand primarily for stabilization. This imbalance created stress that was repeated more than 1,000 times per day.
Westbrook describes that discovery as the quality circle’s “epiphany moment.” But that’s not to say its work was done. Far from it.
“Once they figured out it was a lifting problem, it would have been relatively easy— though also expensive — to buy an off-the-shelf transport system,” says Westbrook. “But the team was determined to find an in-house solution at the lowest possible cost, both in terms of initial start-up and ongoing maintenance.”
So, production team members Joe Lisk and Mike Allard and engineering specialist Ho-Ling Lam held brainstorming sessions, which produced rough sketches on paper. Those, in turn, gave rise to an initial design. By March, that had their first working prototype of a trolley-based system. To help minimize the expense, their ingenious device embraced the concept of karakuri
— or technology driven by some combination of gravity, springs and pulleys rather than an external power source.
How It Works -- Here, a RAV4 door frame is loaded onto the trolley...
...then, with the trolley carrying most of the load, the team member moves the door frame into position...
...where it is fitted into the RAV4's door panel as it makes its way down the assembly line.
Clearing a Major Hurdle
The turning point was finding a way to configure the trolley’s rails so that they didn’t interfere with a “light curtain” that serves as a safety barrier between team members and the robotic welding jigs. This feature consists of a series of light beams that, if blocked by a team member, automatically shuts down the jig.
“We discovered that a 3-inch gap was allowed between each of the light curtains,” says Dan Scott, maintenance team member. “It turned out that was just enough to create a path for the rails. That was a big breakthrough.”
Over the course of several weekends, with the support of production team members Nick Phillips and Shawn Duggan, the team tested and refined their prototypes until they settled upon and installed the ideal solution. Thanks to the new frame trolley:
- No one has to carry that heavy door frame, eliminating the safety concern.
- The time to transfer it into place has been cut by 3.5 seconds, boosting productivity by an additional 40 units per day.
- And by taking the DIY approach, return on investment was achieved in just 20 days.
“Ultimately, it is the feedback from the team members doing the process that is most important,” says Westbrook. “Comments like, ‘My shoulder feels so much better,’ and, ‘How soon can we get this on every door,’ make this kaizen a home run.”
Ergo Cup Winner
Not surprisingly, TMMC awarded this kaizen the Ergo Cup in its annual safety competition. It’s currently in the running for regional recognition among Toyota’s other North American manufacturing facilities. More importantly, the lessons TMMC learned are being shared with those other plants, potentially multiplying the benefits several fold.
“It’s about connecting with our frontline people, engaging them in quality circles and implementing their ideas,” says Westbrook. “Along the way, we are developing our people, strengthening their problem-solving skills and empowering them to act. That’s the key to making an already great operation even better. Mike Allard put it best: ‘Built by team members, for team members.’”
By Dan Miller