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Lean University --
Lean Articles
A tale
of TPM
What do
you do when increased customer demand conflicts with
maintenance needs? Spacesaver Corporation turned to total
productive maintenance.
“It’s
fine to celebrate success, but it is more important to heed
the lessons of failure. How a company deals with adversity
suggests how well it will bring out the best ideas and
talents of its people and how effectively it will respond to
change.”
— Bill Gates, Microsoft
“Failure
is only the opportunity to begin again more
intelligently.”
— Henry Ford, Ford Motor Co.
“Remember,
Charlie Brown, you learn more from your defeats than your
victories.”
— Lucy Van Pelt, Peanuts comic
strip
The day
the line died
The pathway to success isn’t always the smoothest. Gates
dropped out of Harvard. Ford’s first car company, Detroit
Automobile, went belly up in two years. Lucy struggled
mightily as a rightfielder.
Spacesaver
Corporation hit its pothole in 2001. But the Fort Atkinson,
Wisconsin-based maker of high-density mobile storage systems
used the lesson to eventually find plant-floor success.
Spacesaver’s
productivity parable centers on Line 5, located in the
fabrication area of the 270,000-square-foot facility.
“Line 5
produces all of the shelf supports for our plant. It’s
crucial to our business,” says vice president of
operations Jim Muth.
The numbers
don’t lie. The plant makes more than 6,000 shelves per
day. Each shelf requires two supports for the assembly
process. Do the math and Line 5 must produce in excess of
12,000 supports each day.
The line
had difficulties meeting the demand. It ran nights and
weekends to keep the parts flowing downstream. And then one
day, in June 2001, Line 5 flatlined.
“The
crash hit us right between the eyes,” says Muth.
According
to fabrication superintendent Marty Weber, air pressure
issues, oil leaks, a cracked ram shaft, a non-level ram and
air cylinder wear and tear contributed to the crash of the
line’s main press. Looking deeper, the existing
production/maintenance philosophy left the line vulnerable
to such damage.
“We were
in a ‘run it until it dies’ mode, and it died,” says
Weber. “Because of product demand, we neglected the
equipment.”
The
machinery stopped. Demand for shelf supports, however, did
not.
“Line 5
was down for several weeks,” says plant manager Michael
Kling. “Just like that we had to find outside suppliers
that (combined) could produce 12,000 shelf supports a day.
It caused a substantial amount of pain to get back on
schedule.”
In the
aftermath, Spacesaver strongly considered tearing out the
line’s 16-year-old machines and buying new equipment at a
capital cost approaching $1 million.
“It would
have been a major investment,” says Muth. “I didn’t
want to start a culture where buying new was the answer, the
fix-all, when the equipment got old.”
Following
Henry Ford’s footsteps, Spacesaver turned the crash into
an opportunity to begin again more intelligently. The
company found the smarter solution in a lean manufacturing
technique called Total Productive Maintenance (TPM).
Solution
was in front of us
Spacesaver was no stranger to lean concepts. In 1998, the
company was acquired by KI (formerly Krueger International),
a global furniture manufacturer with a lengthy lean history,
headquartered in Green Bay, Wis. In 1999, Spacesaver adopted
several lean principles and experimented with kaizen events.
The next year, it initiated a plant-wide value-stream
mapping project and completed 21 kaizen blitzes.
“The
solution was right in front of us,” says Muth. “When we
had the incident, the equipment on Line 5 was 16 years old.
That’s not old. But at the same time, we did 8,000 to
12,000 pieces per day for 16 years. That’s more than 40
million parts. If we would have made the investment in new
machines but treated it the way we did the current line, we
would have been right back at this point. What drove us to
TPM was its roots in lean.”
TPM is an
integrated set of activities aimed at maximizing equipment
effectiveness by involving everyone in all departments at
all levels, typically through small-group activities. TPM
usually entails implementing the 5-S system, measuring
“the six big losses” (equipment downtime, adjustments,
minor stoppages, unplanned breaks, time spent making reject
product and waste), prioritizing problems and applying
problem solving with the goal of achieving zero breakdowns.
Spacesaver
sought advice from the Wisconsin Manufacturing Extension
Partnership. The talks confirmed TPM as the appropriate
solution.
“With TPM,
we believed we could bring the equipment back to nearly
like-new condition,” says Muth.
How TPM
works
A TPM project typically uses a modified kaizen format and
can span several months. It includes:
Training:
The company selects a team of people, including machine
operators, maintenance workers, supervisors and management.
The process begins with a day of training, simulations and
case studies, plus instruction on how to work in teams. The
team also learns how to collect Overall Equipment
Effectiveness data (see sidebar). OEE is shop
floor-collectible data that documents how long a machine is
actually running, how long it’s down, how many reworks are
needed, and so on. OEE provides an easily applied and
understandable way of measuring machine utilization. It also
serves as a record over time of a machine’s performance
and can be used as a reference guide for future
troubleshooting.
The TPM
team then decides which equipment to target first for
improvement.
OEE
data collection: During
the next three weeks, the first OEE data is collected. This
is done by operators on all shifts. This serves as baseline
data for the project and shows where the problems lie.
OEE
data analysis/problem prioritization:
The team meets to analyze the data and prioritize the
uncovered problems. The problems are categorized according
to the “six big losses” that reduce a machine’s
efficiency. From there, the root causes of these problems
are targeted and corrected.
TPM
implementation: Next,
the team works to restore the equipment to make it as
reliable and productive as possible. Using the OEE data,
high-failure-rate areas are identified and the necessary
repairs performed. Then, daily and periodic maintenance
schedules are established. A 5-S organization and cleanup
project is also part of the process.
To document
progress and improvement, the team continues to collect and
analyze OEE data from the equipment.
Bringing
TPM to Line 5
The Line 5 TPM team consisted of team leader Weber, three
Line 5 operators (one from each shift), one operator from
outside the area, a maintenance mechanic, two engineers and
a representative from purchasing.
“This
project gave us the chance to take a step back and see how
production and maintenance functioned and what the
consequences were for our actions,” says mechanic and team
member Bruce Campbell.
“From
maintenance’s perspective, we had a real problem getting
access to the line. Many times, we were asked to put a
Band-Aid on a machine just to get it back up until the
weekend. Then on Sunday, we could come in and do what we had
to do to fix it right. However, if the production output on
Line 5 was low, the operators would have to work on Saturday
and Sunday. The fix then would be scheduled two weeks out.
It wasn’t the right thing to do. But from the operators’
perspective, they needed the machine so they could get parts
out.”
What is
more important: parts production or equipment maintenance?
Spacesaver pondered that chicken-and-egg conundrum
and decided that “both” was the correct choice.
Utilizing
one of the tools of TPM, plant leaders reassigned a host of
routine maintenance tasks to machine operators. In essence,
operators were given joint custody of the equipment.
“Operators
used to insinuate that maintenance couldn’t keep the
machines up and running. Maintenance would insinuate that
operators weren’t running the machines correctly,” says
Weber. “Joint ownership helped put everyone on the same
page.”
Adds Muth,
“It’s now everyone’s job to ensure that this machine
runs as efficient and productive as possible. The operator
should have as much accountability and responsibility as
maintenance does.”
Operators
received training as well as a daily checklist of preventive
maintenance tasks. The list includes checks for fluid
levels, tool and die condition, and oil and air leaks, and
examinations of pressure and thermal indicators. It also
includes machine cleaning activities.
“They go
through a running PM,” says Campbell. “The operator
checks the machine out for certain issues. That person can
address the minor issues. If anything larger in scope needs
addressing, the supervisor generates a work order and we
take care of it. This allows for more proactive work rather
than waiting for someone to say, ‘It broke because it ran
out of oil.’”
Maintenance
relinquished some of its control in the area of asset health
but, in doing so, found that its time and skills were better
utilized.
“We
didn’t have a problem handing off our knowledge to the
operators,” says Campbell. “I can fill oil. I can do all
of the small stuff. But with the knowledge and skills I
bring, I’m better off focusing on bigger issues. We now
can get into projects rather than firefighting.”
Examples of
maintenance’s shift from reactive to proactive work
includes expanded use of infrared analysis and other
predictive tools, experiments into oil analysis and the
creation of a “fourth shift” that handles advanced PM
tasks on Saturdays, Sundays and Mondays.
A byproduct
of the arrangement has been greater understanding and
teamwork between the two groups.
“When TPM
occurred and we increased our production numbers so
drastically, it wasn’t as big of a deal for me to say,
‘I need the line for six hours in order to fix this the
proper way,’” says Campbell. “There will always be
capacity issues because we are a lean manufacturer and we
don’t build the inventory up. However, we do have the
capability to build things up so we can take the machine
down for six hours.”
Getting
results
The TPM project led to many action items for Line 5 outside
of operator checklists and proactive maintenance. These
include:
ACTION
ITEM #1
Square and level the press.
Goals:
Make certain the press ram operates level; eliminate undue
wear to the slides and gibbs of the press; ensure part
quality is consistent from start to finish; and, avoid
stress cracks in the press frame.
Results:
Spacesaver contracted an outside firm to level and square
the press; during the firm’s visits, maintenance rewelded
the stress cracks in the frame.
ACTION
ITEM #2
Capture leaks.
Goals:
Review the entire line for leaks around fittings, caps,
cylinders, seals and tubes.
Results:
Numerous tubes, pipes and fittings were replaced. Catch
basins and drainage tubes were also installed to catch
overspray of coolant and excess oil.
ACTION
ITEM #3
Totally rebuild the air manifold system.
Goals:
Eliminate all leaks; reduce the number of air controls by 50
percent; and, refurbish or upgrade the air cylinders to
newer technology.
Results:
The entire air system for tooling was refurbished to reduce
the number of controls from 16 to eight. Also, the existing
cylinders were reworked with new bushings that eliminated
leaks. Finally, the controls were relocated to an area
protected from the elements.
ACTION
ITEM #4
Redesign the transfer conveyor between the press and the
riveter.
Goals:
Gain access to the back of the press for working on tooling;
eliminate downtime due to problems with the transfer system;
and, eliminate personnel standing on the conveyors in order
to gain access to the top of the press.
Results:
The conveyor and tooling was modified to easily swing out of
the way. This provided greater access to the rear of the
press for both maintenance on the tooling and the top of the
press.
Easing
the pain
Everyone faces adversity and tough decisions on the road to
achievement. How you handle it determines your ultimate
success.
After
dropping out of Harvard, Bill Gates helped start a little
company called Microsoft. After Detroit Automobile tanked,
Henry Ford created the Ford Motor Company. And on April 21,
1994, after more than 40 comic-strip years of trying, Lucy
Van Pelt caught a fly ball and gave Charlie Brown’s
hard-luck baseball team a victory.
“We had
to have the pain before we saw things clearly,” says Muth.
“It just so happened that our pain hit us during the
busiest part of our business and in one of the most critical
areas of the plant.”
Spacesaver
handled the pain on Line 5.
“Because
of our work, I’d say 30 to 40 percent of downtime has been
eliminated,” says Weber. “Overtime is under control. If
we do work a Saturday or Sunday, it’s because of the
workload, not because of an equipment breakdown.”
Recently,
the company has spread TPM and other lean techniques to
other areas of the plant. Such improvements were critical as
business increased substantially.
“The
business has grown 60 percent in recent years without adding
brick and mortar. And, we still have room to grow,” says
plant manager Kling.
A
large-scale business jump and a more productive plant?
Now that’s turning peanuts into peanut butter.
This article appeared in
the April/May 2005 issue of MRO Today magazine.
Copyright, 2005.
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