Just stop! You’re probably overproducing
December 1, 2020 | 11:37 am CST
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It is critical to understand the eight deadly wastes of manufacturing.

They are:

  • Transportation
  • Inventory
  • Motion
  • Waiting
  • Overprocessing
  • Overproduction
  • Defects
  • Unused employee creativity

In a nutshell, all the bad things that happen in our factories fall into one of those categories.

All eight of them are running around all of our factories, costing us tens of thousands of dollars every day. So why don’t we just fix it? I will quote Taiichi Ohno from his 10 precepts: "Waste is hidden, do not hide waste."

As we travel the globe helping companies implement lean manufacturing there is one thing we always do first because it has the potential to immediately boost productivity. We try as fast as possible to get one of those eight deadly wastes under control. Despite what you might think is going on in your factory, if you do not have systems in place to control overproduction, then I can almost guarantee that is your Number 1 problem.

Overproduction? Not us!

I know what you’re thinking. "How can we be overproducing when everything is late and customers are screaming? There is no doubt, we are under-producing!"

If you look at the word overproducing at face value you might assume the definition would be making too much of something.

That gives us this mental picture of shelves full of finished goods where the only bad effect it’s a little too much inventory, but at least customers aren’t waiting.

To really understand the effects of overproducing we have to zoom in a little closer. We have to examine the output of each work station.

In a perfect world, each station would be balanced, only making what the next station needs. We do not live in a perfect world.

The definition of overproduction is simply "producing more than the next station can consume." And this doesn’t mean the end result is an abundance of finished goods, it actually could be quite the opposite and slowing down your entire factory

The rowboat example

To help illustrate the effects of overproduction, imagine you’re in a rowboat with six other people the objective is to get from one side of the lake to the other in the shortest amount of time.

Your team captain is no fool, and from the available candidates he manages to pick five average people and at the last second gets lucky and finds one young man who has twice the muscles of anyone else on the team. Getting a powerhouse like that will surely secure the win.

Or will it?

What happens to a rowboat when one side is rowing way harder than the other side? You guessed it, you just go in circles.

So, in a rowboat when one side overproduces, as in is producing more power than the other side, you go nowhere.
Waste makes waste

Our factories are not much different when one station is overproducing as in producing more parts than the subsequent stations can consume. The same thing happens.

You spend all your time trying to manage the overproduction rather than adding value for your customers.

The reason overproduction is so detrimental to your organization is it is the single one of the eight wastes that Immediately evokes the other seven, and I mean instantly.

Don’t believe me yet? Let me tell you a little story about a skid of parts.

Station 1 is being measured by how many parts they cut and they have a maverick operator. So each day, Station 1 produces one more skid than Station 2 can consume (1. Overproduction).

At the end of each day, somebody has to come and move that skid out of the way (2. Transportation).

Now, those parts are either on the shop floor or neatly tucked away on a rack and are now considered "in stock" (3. Inventory).

All of this transportation is also being done by one of your dedicated employees (4. Motion).

One thing that historical data keeps teaching us is that wherever there’s a batch, there’s a defect. Whether that defect was caused from moving it around, bumping into it, or operator error from the previous process, we just know whenever there’s a big pile of parts there’s always a bad part hiding in it (5. Defects).

Eventually, we start consuming these parts and stumble across the defect. Dubiously we set out to fix it. Now fixing something that should already be right is doing work that shouldn’t have to be done (6. Over processing).

And this whole time we are moving, sorting, fixing or making too much in the first place, parts are sitting around our shop not moving, and we are inadvertently punishing our customers with long lead times (7. Waiting).

Finally, if you do not have a system in place to actively engage and gather intel from your workforce then you are missing out on your biggest opportunity for improvement (8. Unused employee creativity).

This counterintuitive principle of slowing down to speed up works like magic.

The fancy terminology for this is to "subordinate all activity to the bottleneck."

Then focus on improving the bottleneck. And this is not limited to shop activities alone. Your office can be heavily engaged in overproduction, too.

Identifying overproduction

To quickly find overproduction in your operation, ask yourself these questions:

  • Do I have an abundance of raw goods plugging up my shop? (Your purchasing department is overproducing.)
  • Are there three months’ worth of drawings waiting to be released to the shop? (Your engineering department is overproducing.)
  • Is one work center in your shop always buried in parts? (The station right before them is likely overproducing.)
  • Do you have cabinets built up in your assembly area waiting for doors? (Your assembly area is overproducing.)

If you called us and we showed up at your factory today to help you solve some manufacturing issues, without question the first thing we would look for is who is overproducing and how fast can we shut that off.

Typically, these are sacred cows that need to be slaughtered.

Example: Boss says, "The CNCs must run, never turn off the CNCs!" Or it could be saws or shapers or moulders, depending on what you’re producing.

Find the pile

The easiest way of doing this is to look for the pile.

It can be a pile of paper in the office, it can be a pile of parts on the shop floor. But wherever you find the mountain of extra work, turn off the station before it until the pile is gone.

Then when you turn it back on, pace it to the station in front of it.

You will discover a ton of extra time and floor space you didn’t think you had.

Don’t get discouraged, finding waste, and eliminating it is hard. If it was easy, everyone would do it.

We call it "The Lean Crawl" for a reason.

We are always here to help, and these days we have been forced to adapt ourselves and are having great success helping companies virtually! If you have any questions or need help tackling the overproduction in your factory, don’t hesitate to drop us a line.

Have something to say? Share your thoughts with us in the comments below.

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About the author
Brad Cairns | President/Owner/C-Level

Brad Cairns is the senior principal at The Center for Lean Learning/ Quantum Lean and is dedicated to improving the woodworking industry in North America using lean methods. He also owns Best Damn Doors, a cabinet door manufacturing business in St. Thomas, Ontario. You can reach Brad at 519-494-2883 or [email protected]