Most important, our visual system now signals us
when a job is taking longer than expected. When a
welder starts a job, he scans the bar code and the
clock starts ticking. I now can look up at a screen
and see that a job is getting close to being late. Once
the job is over the time allotted, it turns bright red.
As a team leader, I can see the problem as it occurs and then allocate resources to correct it—
assign more welders, involve engineering, whatever
the welder needs to catch up. We do this to avoid
delaying parts from being sent downstream.
This relates to another core issue: We need the
right skilled people and the right equipment available at the right time. If that doesn’t happen, chances are a job will take longer than expected. But because we’re tracking cycle times, we can catch the
problem as it happens and make necessary adjustments to help. This helps us continually perfect a
foundational part of the job shop business model:
Knowing that when an order hits, we have the available capacity to meet the due date.
Admittedly, all this has a certain “Big Brother” aspect that can be di;icult for some. A company must
have a trusting culture for this to work. Operators
are being timed not to punish them for falling behind, but so they can get the help they need when
they need it—ideally, before a job is late.
People also need to know that timing operations
is essential to everyone’s success. In fact, it helps us
all avoid the chaos and reduce stress—no tearing
down setups, no context switching, no unexpected
late nights. In short, it makes everyone’s job easier
and more enjoyable, and it makes the company
more successful. That’s a healthy combination.
Material and Machine Utilization
Because we manufacture all parts needed for an assembly in sequence, we no longer look further out
into the schedule just to fill out a nest. This would
increase work-in-process and make an already complex part-flow situation even more complex.
At the same time, we’re a stainless steel shop; our
material isn’t cheap, so we still need high material
utilization. This means we’ve needed to become experts in changeovers and remnant management. A
laser might run 30 di;erent grades or thicknesses of
stainless every day. We’ve perfected our changeover
procedures so that we get a good part the first time.
When programmers run out of pieces that fit on
a nest, they stop. The machine cuts what’s needed
and an operator prints out a bar code label and
places it on the remnant. Remnants are stored near
the machine for later use and organized by material
gauge and grade for quick retrieval. When a new job
arrives to be nested, the so;ware first checks for
remnants before it places parts on a fresh sheet.
We also now take a di;erent approach to machine
setups. Years ago we’d group like jobs together to
increase machine uptime and reduce the number of
changeovers we had during the shi;. This increased
uptime and made traditional e;iciency metrics look
great, but in doing so, we slowed part velocity. A
brake operator would spend an extra hour bending
parts that weren’t needed immediately. Meanwhile,
the parts that welders needed sat in queue waiting
to be formed.
Ultimately, the longer it took for parts to flow
through the plant, the greater it cost us. Part veloc-
ity is what matters. Sure, excessive downtime on a
machine can cause part flow velocity to slow, but so
can a lot of other things, like flooding the floor with
work that’s not needed immediately.
To fabricate sequentially, we needed to become
setup experts. Sure, by changing over a brake five
times in an hour we’ll have less machine uptime,
but we’ll have higher part-flow velocity because
we’ll be forming everything the welder needs as
soon as possible.
We do use a little common sense here. If, say, we
have three jobs on the schedule for the press brake
operator, and two have nearly identical setups, we’ll
schedule those two back-to-back. But all three of
these jobs need to be shipped at similar times. We
never bend more parts than needed (to have parts
for the next time the job is ordered) or bend another
job that’s due a week later, just to save a little on
The Role of Software
A final element to all this is the scheduling so;ware.
We use our scheduling module in our enterprise re-
source planning (ERP) system. In truth, if we were
sequential manufacturing in a low-product-mix as-
sembly line situation, the act of scheduling would
be far simpler. We’d balance the line, schedule se-
quentially based on the established takt time, and
that would be that.
But we don’t have consistent takt times, nor do
jobs flow in a linear path. Routings bring parts to
multiple shared resources at various times, with
various manufacturing steps—laser cutting, sawing,
deburring—happening at di;erent times (
technically called concurrent sub-jobs). All these pieces need
to be sequenced to arrive in welding and assembly
at nearly the same time. We need to calculate all this
while factoring in the hundreds of other jobs in the
For us, this is where advanced so;ware has really
helped. As long as we feed the right data into the
scheduling system, it will help us schedule jobs so
that they all arrive at welding and final assembly at
the right time.
Because we’re running sequentially, the so;ware
times orders so that they’re released to the floor
when we know we’ll have everything we need to finish the job. If we release before that, there’s a greater
chance that a job could arrive at welding or assembly before purchased components are available.
The leadership team reviews the schedule during its morning huddle. Photo courtesy of Ace Metal Cra;s.
Keith Stout points to the shop status board and notices jobs that may need attention. Photo courtesy of Ace Metal