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Lean University --
Lean Articles
Lean
manufacturing cuts waste, raises quality
Lean initiatives in F-2
production are achieving significant results at Lockheed
Martin Aeronautics Co. Time reductions have become the rule,
as Six Sigma audit scores climb and quality improves.
Among
the variety of items that the Fort Worth plant produces for
Japan’s new F-2 fighter, the most challenging is the
co-cured, composite wing box. Prime contractor Mitsubishi
Heavy Industries
designed the wing box, and LM Aero adheres to MHI’s
fabrication and assembly processes. LM Aero began delivery
in March 1999 of wing boxes for F-2 production aircraft. The
company will manufacture 80 percent of all left-hand wing
boxes – more than 100 units – during the life of the
production program, anticipated to last beyond 2010.
An
F-2 Lean team was formed in Fort Worth last August. The
team, with the help of lean consultants, charted a detailed
course toward meeting several goals; these include
reductions in man-hours and total span time, as well as
higher Six Sigma audit scores and improvements in quality,
safety and ergonomics.
 As
a result of the team’s initial lean projects, improvements
have been significant. Here are a few examples: man-hour
reductions of 60 percent in painting, 50 percent in lower
box trimming and a 25 percent reduction as a result of
point-of-use kits and ergonomic enhancements. The distances
employees travel to locate parts and equipment also have
been reduced: Two stations improved by 57 percent, while
another turned in an impressive 87 percent reduction.
Improvements also are being noted in Six Sigma examination
scores. At one F-2 station, the rating improved by 60
percent.
Lean
does not require that employees quicken their pace; it
requires improvements in efficiency. Less waste, not haste.
So the team embarked on a mission to eliminate the seven
forms of waste: overproduction, idle time, excessive
transportation, unnecessary processing, stock, wasted motion
and defective products.
For
example, detail line analysis uses videotaping of processes
as a key tool to help identify waste. Like a professional
football organization, the lean team videotapes each play of
the game (process). They analyze the tape to determine how
well the processes work compared to what is expected.
Using
the tape, the team determines what changes are needed to
improve product quality and build-time efficiency. In some
areas, for instance, the video revealed workers spending a
great deal of time collecting the right tools and equipment
to perform tasks. To eliminate unnecessary travel time,
point-of-use kits were created; these contain all the needed
items and puts them within easy reach.
Video
replays also showed how cumbersome it was for assemblers to
work on the wing in a transport dolly.
Thus, ergonomic improvements were implemented,
leading to a new, simpler fixture and work area layout that
helps to improve part quality.
Other
changes also have been implemented that are contributing to
impressive results. Many are still in work. The F-2 team
continues to apply lean processes so LM Aero can meet its
overall goals of reduced span times and improved part
quality for the entire wing-box-assembly process.
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