We quite often get calls, or find ourselves in a conversation where somebody is
inevitably asking “what’s the leanest way to lay out my factory”?
This is always a delicate subject because it is important that all machines are located in
the right spot based on lean principles, but it’s not that decisive. there isn’t a lean
layout, and a not lean layout. We have to remember the essence of lean is continuous
improvement, which means everything is changing all the time. Whether we like it or
not, that includes our brian, our processes and yes, our factories. So as you read on
and develop a plan for where you’re going to put all of your equipment and
workstations, keep in mind rule number one of factory planning is “no monuments”.
Check out this youtube video on monuments https://youtu.be/YahEUkJI7Xc
To illustrate this point, at my own
factory our maintenance engineer
threatened to put our CNC routers
on wheels we shuffle the factory
around so much. This was officially
the fourth time in 12 months that we
moved around are entire factory.
And I don’t just mean we moved a
table saw. I’m talking about
complete factory makeover, we
moved every single machine,
electrical connection & dust pipe,
yes, the whole kit & caboodle.
It’s really important to step your way through the process from receiving the material to
shipping the product one step at a time. Don’t think about step 10 while you’re thinking
about step one. Just think about how do we unload trucks, make that as efficient as
possible. Then when we transport raw goods to our machinery, how do we make that
distance as short as possible. If you’re thinking about assembly and packaging at the
same time you’re thinking about loading machines, you may skew reality at step 1 for
what you think is going to be good for step 10.
Here are 7 steps that should dramatically help improve your layout planning.
Step one: At the heart of a good factory layout is one pretty easy concept. All we’re
trying to do is reduce the distance a component travels from the time the raw material
comes in the door, until the time the finished goods leave the building. Inside of that
there are all kinds of concessions that need to be made for people and machines. But
this is the ultimate goal. I will quote Henry Ford when it
comes to plant layouts, he said “machines should be
as close as they can possibly be together, but they ought not to be one inch further away than they have to be“.
Step two: Find a way to get a scale model of your factory and all the machines this can
be as simple as paper and a cork board, or as advanced as 3-D modelling. The moral of
the story is use what you got! Some of the best success I’ve had with plant layouts we
actually cut out wooden blocks of all the machines so we could move them around like
board game pieces. Or scraps of paper on the kitchen table get the job done as
well.(see picture) The only trap here is
falling in love with your first idea, make
sure you wipe the slate clean and come
up with at least three or four possibilities.
A great way to accomplish this is to
include your team give everyone a Voice
on the new layout, try to incorporate one
small idea from everybody. This will
minimize the pushback from the
production staff when you finally make the move.
Step three: Identify your bottleneck. The reason you need to know your bottleneck is
because you have to protect it. Any other station in your factory can go down for a short
period of time without affecting throughput, except your bottleneck. So you want to
make sure you put a buffer of work before your bottleneck. And a “just incase” area
after it. The buffer before the bottle neck should always have a predetermined amount
of work. A half a days work is really tight, two days work would probably be a little too
much. How do you determine this deciding how long are you going to need to fix your
most likely break down. So if that bad thing happens the bottle neck can keep working.
And the “just in case” area should be able to hold the same amount of work in the event
the bad thing happens after the bottle neck.
Step four: You’re gonna need to have a
good idea of statistical fluctuations within
your factory. For example: if you’re a
cabinet shop (abiding by the 80/20 rule of
course) within that 80% of your
production, what is the fastest thing to
build, and what is the slowest thing to
build? and then make sure your work
buffer between stations will not run out of
work based on that calculation. This
means if you have 2 stations working an
assembly line. Station 1 ends up with the
slow build item, station 2 does not run out
of work before station 1 completes that
task.
Step five: you should have a really good idea of how much you want your factory to
produce. You can build a lot of assumptions around some pretty reliable averages in the
cabinet making world here are a few
1.8 man hours per cabinet is good, if your above 4 hrs I would consider calling in some
outside help.
Batch sizes between 10 and 15 cabinets usually work out really well
1 CNC Can cut between 80 and 120 sheets per day when you're cutting cabinet parts.
If you’re a kitchen producer, don’t underestimate your finished goods storage. You know
as well as I do, contractors are never on time!
Step 6: try and build in some flexibility with your layout. The only things that really keep
a machine and one spot is air, electricity & dust collection. A good idea is to roll up
about 10-15’ feet of wire above the machine so if you find you need to move it a bit one
way or another, it’s not a big hassle. Your other challenge is always dust collection the
snap together pipes are great for this purpose, albeit expensive, so if that’s not in the
budget, just get good at cutting pipe.
Step seven: test your layout before you move anything. Some good measurables are
A) total linear feet travelled from start to finish
B) total WIP
C) # of people required
D) physical steps of each operator to complete their task
And there’s nothing that says any of these measurements are right or wrong, just try
and improve them with every iteration of your layout.
And last but not least, it never hurts to ask a friend or a professional to give it a once
over. There’s a good chance you’ve been staring at it for a week and could be blind to
some obvious improvements, or at least you can sleep at night knowing somebody else
has validated your ideas
PS- There is also one other factor when it comes to layouts, just remember you can’t
get everything right the first time! expect some hiccups and some bumps in the road.
Accept you may have to move a few things that are a real pain in the butt after the fact.
So long as you’re expecting this to happen, then it’s not such a daunting task when it
does
Now, stop reading get out into your factory and just move that thing you’ve been dying
to move for three months. FIX WHAT BUGS YOU!