| The following are prime,
preliminary indications that your company is a candidate for a Nested-Based
CNC work cell: If your company uses 15 sheets of material
or more per day and/or you have two full-time employees performing
sawing, routing and shaping operations you should consider a
Nested-Based CNC work cell. Just because you begin the justification
process with one type of production method doesn't mean you shouldn't
consider alternatives for your company. For example, should your
company have extensive horizontal boring requirements it may still be appropriate to design a Nested-Based work cell that includes
a bore/dowel insertion machine. Because the machining cycle in
a Nested-Based cell is relatively long, an operator has four to
eight minutes in which time he/she could be horizontal boring and
doweling panels.
For the purpose of justification always
use a lease payment because it is easy to calculate and will
allow you to quickly develop a monthly machine expense. Keep
in mind that it doesn't matter if you lease a machine, finance
it or pay cash and forgo the monthly interest on your money - there
is a monthly expense associated with your machine tool acquisition.
An equipment lease may provide you with some significant tax
advantages by allowing you to write-off your monthly payments
as an expense while reserving your line of credit with your bank
for cash flow. Monthly lease factors change
almost daily; check with your machine tool distributor for the current rate.
Machine Justification Components:
Two Person Labor
If you have two or more employees sizing panels on a saw, machining
rabbits, cutting dados, sawing back grooves, boring holes, shaping
parts, machining pockets, handling parts from station to station
or any other operation that could be replaced by a CNC router,
you should be able to justify a Nested-Based work cell. For example, If your lease payment
is $3,960.00/month your
annual expense for the Nested-Based work cell is $47,520.00.
If your billable shop rate is $30.00 per hour you will only have
to replace 1,584 hours to justify a Nested-Based work cell. This
is less than one person! If you replace (or displace) one person
($62,400.00/year at $30.00/hour) your company will pay for the
Nested-Based work cell plus make an additional $14,880.00 in
profit the first year. If you replace two people your additional
profit will be $77,280.00 and three people will be $139,680.00
and so on. Most business owners and/or managers don't realize
that they are already paying the equivalent of machine payment
in wages.
Fifteen Sheet Daily Use
If your company uses an average of more than
fifteen sheets of material daily, you can justify a Nested-Based
work cell as follows: A Nested-Based work cell will produce a
panel every four to eight minutes with one operator. With an eight minute
cycle time, fifteen sheets of material can be produced in two hours,
leaving the rest of the day for assembly. Your cost per sheet
processed is minimal, as well. If you use the lease number from
above ($3,960.00/month) and divide it by your monthly material
consumption (300 sheets), your cost to process a sheet of material
turns out to be $13.20 plus 40 hours of labor and overhead. If
you use a labor rate of $30.00/hour your total labor cost to
process 300 sheets is $1,200.00 The numbers become even more
impressive as your volume increases and your cycle time decreases.
Can't Find Good Help
It is very difficult to find good
employees. Well-trained people are in very high demand. After you have spent
the time and money to train an individual they soon become the target of
other employers. A Nested-Based work cell will provide your company the
ability to have fewer higher-paid employees that have a future with your
company and are less likely to leave. A Nested-Based work cell also allows
you to be far less dependent on even your best employees because the
required job skills are definitive and trainable. As you can see, if you
need to hire an employee, you already have a great justification for a
Nested-Based work cell.
Material Handling
Material handling is an important
reason for the justification of a Nested-Based work cell. In most cabinet
shops and store fixture manufacturers, shop personnel spend as much, or more
time handling, stacking and de-stacking parts as they do processing parts.
This can be quickly identified in your shop if there are stacks of parts in
front of and in back of several work cells. Keep in mind that on a
Nested-Based work cell, an operator loads a sheet on a CNC router, hits the
cycle start button, and then has four to eight minutes for secondary
operations. There is no material handling in a Nested-Based work cell.
Setup
With the high-volume vacuum pump of a
CNC router and flow-through vacuum work holding, there is virtually zero
setup time in a Nested-Based work cell. This work cell can literally produce
one part at the same rate it can produce one hundred. This is a critical
advantage over manual machines that need to be adjusted for every part or
series of parts. This also has a big advantage over a CNC point-to-point
machine because there are no individual programs to write or load, no rails
to adjust, and no special considerations to be made for through-cutting.
Keep in mind that no machine in any shop makes a dime for it's company
unless the tool is into work! If a machine is down for programming, setup,
maintenance etc. it isn't making money.
JIT
Because the Nested-Based work cell has near zero setup, it provides
Just-In-Time (JIT) manufacturing capabilities. This allows a
company to become a great deal more responsive to fluctuating
sales while at the same time substantially reduce inventory.
Rework
Rework is almost a non-issue in a Nested-Based work cell. Because
this work cell can efficiently drive production to a lot size
of one, damaged components can simply be re-introduced to the
system.
Floor Space
A Nested-Based work cell can function in as little as 250 square
feet. This takes up far less floor space than a beam saw and
CNC point-to-point combination, or several smaller machines. Operating
in a JIT environment also reduces the space required for inventory
of components ready to assemble, and stacks of work in process
components at various work cells.
Predictability/Scheduling
Because the part quality and output of a nested
based-work cell is so predictable, scheduling is very easy. The
machine sets the pace and produces same number of high quality
components many hours per day, no matter what day of the week
production occurs.
Peaks in Sales
Very few of us work at a company that
doesn't experience fluctuations in sales and backlogs. Because of the raw
production capacity of a Nested-Based work cell, a few hours of overtime or
one operator on a second shift can keep up with the most radical spikes in
sales volume. The type of people that you will need to add, if any, will be
lower-skilled employees (or temps) primarily for assembling.
Quality
Increased quality is a given in a Nested-Based work cell. Every single
edge is machined instead of saw cut, and parts are sized to the accuracy of
a CNC router, which is far more accurate than a saw. There is also no
potential of operator error because the CNC router is completely processing
the components. Edge banding a machined edge is also superior to banding a
sawed edge.
Assembly
Because parts produced in a
Nested-Based work cell are extremely accurate, assembly is a breeze. Many
companies report that they justified a Nested-Based work cell on the labor
savings for component manufacturing, but that the reduced labor in assembly
is actually as great, or greater, after work cell implementation. This is an
extremely hard thing to quantify prior to implementing a Nested-Based work
cell. You will see significant savings in assembly time.
Peace-of-Mind
Higher margins, less labor, more coordinated production, better quality
products, and increased general predictability provide a great deal of
peace-of-mind for company management and their employees through
Nested-Based Manufacturing.
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