Shop smart
by Dennis Sowards
January 1, 2010
Lean forces new thinking when buying machinery
Spending money for equipment is always a
challenge for contractors. Everyone wants top value for his or her investment.
Typically
contractors compare the cost of the equipment to the projected return.
Considerations usually include the capacity and speed of the equipment — more
is considered better — maintenance costs and warranties.
Steven
L. Streimer, vice president at Streimer Sheet Metal Works Inc. in Portland Ore.,
says they would look for “one machine for a given purpose that is capable of a
broad range of product variants. Such as a spiral machine that produces duct in
28-gauge through 14-gauge materials.”
At Streimer Sheet
Metal they have been implementing lean practices in their shop for several
years. Lean has changed how they look at everything.
Streimer
puts it this way: “Knowing about lean, we now realize our previous decision
criteria has been all wrong. Not only have we, in many cases, paid too much for
a machine capability which is only used 10 percent of the time, but by doing so
we have also handcuffed our ability to streamline the setup process. Looking
further at our historical decision criteria, we now know it makes little sense
to have a fast machine when the operator has to stand at the machine anyway and
could be used for a different task and/or only to have the fast machine now sit
idle while the rest of the process gets caught up. We now find ourselves
looking for equipment which fits a specific task, has limited setups and fits
well within the rest of our value stream.”
Criteria
Especially when money is so tight these days,
contractors who are applying lean principles should incorporate some additional
criteria in selecting sheet metal equipment.
Running a shop
using lean techniques is a different way of thinking about how work is
fabricated.
Lean focuses on product flow in small batches.
Lean is often counterintuitive to traditional shop-process thinking. It
organizes the work not by function — welding, insulation, etc. — but by product
type. Lean tries to eliminate waste, which includes fabricating product too
soon, product waiting, movement by people as well as material movement,
unnecessary steps, inventory, and of course, defects. This might
mean:
• Instead of running expensive machines like a plasma
cutter at near capacity, it may be better operated at maybe 70 percent to 80
percent capacity or less.
• Building one fitting at a time
rather than many fittings in a batch mode. • Not building
products until the field needs it, instead of fabricating duct weeks ahead and
stockpiling it at the shop or sending it to the jobsite early.
•
Matching the material fabrication to the capacity of the slowest station rather
than running each area independently and stockpiling work-in-progress inventory
at the next station.
For example, there was once a shop that
burned so many jobs and put each on rolling carts that they ran out of the
carts. This limited downstream operations that needed the carts,
too.
• Focusing on having tools and needed parts at point of
use to reduce “treasure hunts.”
• Making sure that equipment
is properly maintained and correctly operated so it functions when
needed.
• Minimizing the time it takes to change over a tool
to a new size or metal thickness, such as a plasma cutter or a large brake
machine.
• Not measuring pounds per hour, but cycle time,
percent of material fabricated right the first time, and the percent the shop
delivered as promised. These are better measures for evaluating shop performance.
•
Separating the operation of a machine from the operator. Watching a machine
work is waste. Lean seeks to use machines that can operate autonomously and
will signal the operator when the job is done, when a defect is produced, or
when any abnormal situation happens.
Consider this
When lean is taken seriously in a shop,
productivity will improve by 30 percent or more.
When new or
even used equipment is being considered for a lean-operating shop, here are
some primary considerations:
Is the equipment built by a
company that itself is doing lean? If so, it is more likely to meet its
commitments for on-time delivery, quality and performance. All salespeople will
claim they can deliver a quality product on time, but not all do.
Look
at install requirements including time. No matter who does the installation and
startup, the process should be user friendly.
Smaller is
better. You don’t need one super machine that can run large volumes of duct super
fast, unless you only produce one type and size of duct. Smaller equipment
offers more flexibility to meet the variable flow demands and smaller
batches.
You want a machine that is easy to run with a quick
learning curve for the operators. The less steps the better. You want one that,
if possible, does not need watching while it runs so the operator can be
setting up the next job or doing another task. The equipment should include
signals and mechanisms that will notify the operator of abnormal operations.
Operating instructions should include checklists and possibly visual diagrams
and pictures to easily show how to run it.
Especially
important is to have equipment where setup and change-over can be done in the
minimum time with good ergonomics.
The equipment should be
easy to maintain, with maintenance instructions clear.
Where
possible, you want to use gravity to help. We want to go from a higher level to
a lower level to feed the machine, and when taking product off of it when
done.
Lean work requires flexibility to move equipment
around to meet the ever-changing product requirements. You may not be able to
move the plasma cutter around but may be able to move other machines. The ease
of moving the equipment should be considered.
Like buying a
car that has unique parts or tools that are hard to find and expensive to
replace, we want equipment with simple common tools and replacement
parts.
To minimize “treasure” hunts, lean seeks to put the tools
needed for running or adjusting equipment right on or next to the equipment
itself. If the equipment manufacturer is doing lean, the company will
understand and design its equipment for this need. If not, look at what tools
are needed and if there is space on the equipment to put the
tools.
One other interesting approach, not always used by
contractors prior to applying lean, is to involve those who use and/or maintain
the equipment every day in the decision-making process. This gives trust and
ownership to the operators and they in turn look for ways to do lean.
Consider
used equipment as a better alternative than purchasing new. Used equipment may
be especially useful where the need is low, such as a line of products made
less frequently. This could free a better machine for the fabrication of the
main product lines.
The last idea, which really should be
the considered first is: Do you really need the equipment? A basic lean
principle is to use creative thinking rather than money. By looking in detail
at the way material is fabricated, one may discover that more productivity can
be generated through applying such lean tools as the Five S and Kanban, and no
new capital equipment is needed.
Dennis Sowards is an
industry consultant and author of the research book Thinking Lean — Tools for
Decreasing Costs and Increasing Profits, funded and published by the Sheet
Metal and Air-Conditioning Contractors’ National Association-affiliated New
Horizons Foundation. His company is Quality Support Services Inc. and he can be
reached at dennis@YourQSS.com or at (480) 835-1185.
For
reprints of this article, contact Jill DeVries at (248) 244-1726 or e-mail
devriesj@bnpmedia.com.
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