Would you say your factory is completely under control? You know exactly what’s
going on at each station, your people know where they should be, and when,
everyone knows whether they’re having a good day or a bad day in a glance and
you know exactly what data to base every decision in the entire factory on? If this
is you, you can stop reading.
If your factory feels more like the tail wagging the dog, and every day starts with
that sinking feeling a cowboy has just before the gate flies open on his bucking
bronco then this one’s for you.
Factories are an extremely complex living organism where things are changing in
a moments notice and if you’re trying to react to each and every one of those as
they happen, then oh boy, you’re in for a rough ride !
For this lesson we’re going to dig into our TOC toolbox, (theory of constraints)
and think like a physicist. You may, or may not know that a core belief shared by
all physicists is “there are no complex systems in reality”. So, if something is
complicated, it means we have created it. Yeah, I know it sounds crazy and
you’re wondering how does it fit into my woodshop?
Consider for a moment, your shop has 30 work centres from sales to engineering
that all need management, and that any moment one or more could go wrong. A
physicist would look at that and say right off the bat “30 is too complicated, must
be less”. So then the search begins for which one work centre determines what
happens at the other 29. And how do we know it’s one? Well, we don’t. But that
is the core belief, so we search for it. I will give you a short cut, one is in fact the
right answer.
Now rather than go searching for who knows how many lifetimes for where this
point may be, I prefer the a more controlled method, and I create it. This is what
we will refer to from here on in as “the control point”.
If you’ve made it this far, congratulations you’re in the top 5%. We usually lose
people right around. There are no complex
systems in reality… Lol.
Let’s continue. First, let’s discuss where the
control points should be, I suppose technically
it could be anywhere, but I prefer somewhere in
the middle of the whole operation. This allows
us to create several feeding operations and
several following operations.
Generally, speaking, the control point is typically where assembly happens.
Next step, calculate the process time of the control point. This is very easy since
this point will determine the throughput of your entire organization. What does
that have to be in order to meet customer demand and/or profitability targets. For
this example, let’s say you have to make 100 widgets per day. Get some good
data on the capacity of your control point, and in this example of 100 widgets per
day we have 4.2 minutes per widget. Set up your cell so it has the ability to do
this with a small buffer of time let’s say between 4 and 4.2.
Well, the hard parts done!
Since this is the point at which we will determine the
throughput of your entire factory, and
it’s calculated at what the company
requires, [trick question incoming]
Can this station ever run out of work?
If you said no, you’re only sort of right.
“No” does not have the level of
urgency that I’m talking about. If you
said heck, no, never, oh my God no,
then you’re barking up the right tree.
When I say, never, I mean never! so
you have to protect your control point
at all costs. Now that I’ve got you all worked up, don’t worry there’s an easy way to do it.
All we have to do is put a buffer of work right before the control point. The size of
the buffer is determined by Murphy’s Law, how big is Murphy? What I mean is
when things go wrong in any of the feeding operations how long till you’re up and
running again? That’s how big the buffer should be, so when the typical things go
wrong, your control point never runs out of work.
Good news you’re on the homestretch. You need one more very important
buffer, and this is after your control point, it should be about the same size as the
buffer going into the control point the only
difference is this one should stay fairly
empty. The
only reason we have it is so if something goes wrong
after the controlpoint we have somewhere to keep putting product until the problem is solved and
flow is resumed again. Protective measures so the control point never stops.
The only thing left to do is go to all of your feeding operations and all of your
following operations and make sure that they are just slightly faster than the time
set at your control point. In this example we set 4.2 minutes at the control point I
would ensure that all feeding and following operations are between 3.8 and 4.0.
If this system is set
up right, it should
force the shut down of work centres
around the shop every now and then,
the only one that works 100% of the
time is the control point. If you try and
balance all your stations at the exact
same time, that would mean when
one misses a beat they all pay that
penalty. You want to have built in the capacity
to deal with a problem and the ability to catch back up without affecting the control point.
Check out our video from one of the best companies we’ve ever worked with, where we implemented this
strategy, and saw a rather significant increase in throughput.
www.youtube.com/watch?v=OnxsTJUPKcw
Control points also offer solutions too many other
questions, where should I invest capital?, which
machine should I buy?, do we need to hire more people? Knowing the heart
beat of your factory lets everyone make better decisions.
If you need help setting this up in your factory, we’re only a phone call away, if
you enjoy small doses of lean each day, consider following me on TikTok, search
for lean maniac where we do daily tips and tricks.