November 14, 2006 The moving production line concept was around for more than a century before Henry Ford famously used it to speed output and cut costs and hence transform the automotive industry a century ago. So do we now know all there is to know about manufacturing efficiency? Not by a long shot! The Boeing Company has just started using a moving assembly line for the first time to build its market-leading 777 jetliner. Earlier this year, Boeing began work to transform its 777 assembly line into a leaner and more efficient production system. This initial use of a moving line during final assembly represents substantial progress with that transformation effort. Assembled one-by-one, it takes 26 days to assemble the 777’s three million constituent parts, but with a moving production line, the aim is to cut that time to just eight days. For now, the moving assembly line is used only during final assembly positions for the airplane, moving it at a steady pace of 1.6 inches per minute during production.
"A moving line is the most powerful tool available to identify and eliminate waste in a production system," said Elizabeth Lund, director of manufacturing for the 777 Program. "A moving line drives efficiency throughout the system because it makes problems visible and creates a sense of urgency to fix the root causes of those problems."
In addition to productivity and quality improvements, Lund stressed the new production system enables greater involvement and support of the people who build the airplanes. Assembly mechanics have been involved with planning and designing the new production system and they will be one of the primary beneficiaries of it.
"We want to make it easier and safer for our employees to do their jobs by providing them the parts and tools they need precisely when they need them," said Lund. "It's similar to the team of people supporting a surgeon and ultimately the patient in an operating room."
To make its 777 assembly line move during final assembly, Boeing uses a tug that attaches around the front landing gear of the airplane and pulls it forward. The tug has an optical sensor that follows a white line along the floor.
During final assembly, mechanics install items such as seats, overhead stow bins and other items on the interior of the airplane. In addition, functional testing is performed on the various systems in the airplane and the engines are attached.
Boeing intends to complete a continuous, one-bay moving assembly line for the 777, which will include systems installation, final body join and final assembly for the airplane, sometime in 2008. This will be the most extensive moving production line used to build a commercial airplane.
The 777 family of airplanes is the market leader in the 300-to-400-seat segment, consistently capturing more than 60 percent of that market since the airplane was launched. To date, Boeing has sold 851 777 jetliners, with 46 customers around the world that own or operate the efficient and passenger-pleasing twin-aisle airplane.