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A Lean Fairytale – Improvement is like Onions

You know how in Shrek, there is that one iconic line, “Ogres are like onions?” Well, I think that improvement transformations are a lot like ogres, I mean onions.

When you tour a company with a truly lean vibe going on, there are some things about it that just gives you ‘hero worship’ vibes:

  • Wow, that is so cool
  • How are they so organised…..and clean?
  • Look at those lines on the floor
  • I want KPI boards like that

And so on. One never fails to leave a company that is hitting it out of the park with improvement without being inspired, and feeling a little intimidated and hopeless. You see, it’s hard for us mere mortals to even imagine our own companies or processes reaching that stellar or imagined level of awesome. But we are hopeful and motivated.

We rush out, get ourselves a shiny new consultant and get started, knowing that its only a matter of time before we too can experience the Zen state of the truly lean. If only it were that simple.

The fact of the matter is, it is often the sheer volume of what needs to be done that pushes us off the glass bridge of lean. It’s overwhelming and there’s just so much that all has to be organised all at the same time. No one could possibly make a plan for every part, right? Right?

Well, wrong actually but here’s the wonderful secret about onion improvement.

Once upon a time

There was an amazing company that had the most awesome and beautiful products around. In fact, this company was making thousands of these products a year.

This company was also into improvement, and was just starting to learn about a thing call ‘lean’.

This story is about the area of the company that was responsible for folding the sheetmetal parts that went into the product. Parts for every product were cut on sheetmetal cutting machines and then folded in press brake machines.

Layer One

Embracing the concept of ‘just do what’s required’, the company had a method for folding everything that had been cut the previous week. Simple, easy and effective. No wasted pesky administration, everyone knew what to do. Everything was well in the little kingdom company.

But not for long….the products made by the company were so awesome that soon the folding department could no longer keep up with the new demand. It was now taking, 6, 7 and then 8 days to fold a week of cutting. It was a disaster, there were parts everywhere. The supervisor and the plant manager were wading through piles of sheetmetal. Everyone despaired. This was the only way they knew how to produce. What would they do now that a week was 8 days instead of 5? In only a short while, they would run out of fingers to count on! They needed to do something!

Just then, someone asked an insane question. “Do we actually use all the things we fold each week on the product?” The others stared in shock. “Well of course not, This is Re-Order Point (ROP) Control. We just put back what we used 4 weeks ago. This has nothing to do with what we’re going to need next, our system is designed to make sure that there’s always stock for what ever happens next!”

“So, maybe we should just start folding next weeks’ work then?”

Layer Two

Everyone was happy, the team had started folding only what was going to be used next week. For sure, they were folding all of the parts of any type that were needed, regardless of the quantity. This was only right though, because everyone knows that its inefficient to do too many set ups. Much more efficient to fold it all at once.

The supervisor and the manager were uneasy though, they at least were still wading through the parts on the floor. They were folding in the right order now, but there were still parts to the ceiling. Stillage after stillage of ‘extra’ parts loomed over them from row after row of immensely tall pallet racking. It filled them with a sense of impending dread. Just then, a piercing cry of despair echoed through the sheetmetal storage area. They dashed to the source of the sound, only to see one of the folder operators. The distraught team member was sitting on a reach truck, a full stillage loaded on the forks. His eyes were bleak and empty. The supervisor and the manager could only make out a few words between his hopeless sobs.

“Went….to put……away…..folded 200. But…..there are…..already two…other stillages….up…there……what….was….point…my….work…hours….spent…..meaningless? How many….needed….really?”

The manager and supervisor were appalled. Reality dawned upon them like the sharp slap around the head by the gods of lean. Why were they making things they didn’t need at all? How many were needed anyway for the next week? 40? Why on earth did they have 600 of the blasted things? Just then, an imp of darkness engineer from the product design department popped up out of nowhere and handed the manager an engineering change note for the part the operator was still sobbing over. They needed a critical change and all the parts would need to be discarded and replaced. The manager sighed deeply. Overproduction truly is the worst Waste.

Layer Three

The manager and the supervisor decided that enough was enough. They were tired of coming across sobbing team members amongst the forest of sheetmetal racks. It seemed insane to keep folding things that they didn’t need, but how could they move forwards? The scary wizard manager that controlled production scheduling and supply chain was notorious for saying “No” first and asking questions later. He was a good guy though just not fond of stupidity. With only a little persuasion and bribery, he was convinced to join the noble cause. He explained that he was using the same method to control internally made sheetmetal parts as he did to bring in externally sourced purchased parts. As a result, there was around 5.5 weeks of folded sheetmetal parts in the racks. The supply manager, however, was reluctant to change this method, because this way, he knew that there would always be enough parts and production would never stop due to a shortage.

They did however, manage to reach an agreement. Why not, just fold smaller quantities at any one time without changing anything else? This would mean that the folder operators would only fold what was needed for the next week, keeping some of the parts as flat stock. This seemed like a great idea to everyone. There were just two big problems.

One: The flat parts storage racks were only designed to take a week’s worth of flat parts and were already overflowing. Where would they keep the additional parts that wouldn’t be folded?

Two: Folding in smaller batches is inefficient. Everyone knows that – d’uh. There would be a massive cost in lost productivity if they made smaller batches. On top of that, they would have to fold everything for each product being made, every week. They weren’t doing that now, ROP just kept the products rolling fairly randomly. It was impossible to know if there was enough time for this. And who knows how many folds there are in product anyway…..

Layer Four

The manager and the supervisor and the supply manager all stopped at once. How many folds are in product? Nobody knew. How was it that nobody knew? The company had been making products for over 10 years. Nobody knew because it wasn’t important, until now.

A few seconds later, the next question surfaced. “So how many folds per hour can we do on a machine anyway?” Nobody knew that either. The manager and the supervisor felt a little bit inadequate. The supply chain manager pretended not to notice. “Never mind, we can just find out. How can we move to the next stage without knowing if we even have the ability to do what we want to?”

The manager and the supervisor were inspired. They immediately began to work feverishly on the new project. Every product was reviewed, drawing after drawing analysed and the folds counted. Every machine operator began to record their time, to establish the elusive ‘folds per hour’ rate. Spreadsheets of great renown and longevity were created. The pivot tables of destiny were born.

At last, after many weeks of toil, they had two very important details:

One: The number of folds per product

Two: The average fold per hour rate for the folding machines

From this information, they could now calculate the two magical phenomenon known as “Cycle time” and ‘Capacity’.

It was a new era.

Layer Five

It was as if they had opened a door into a wondrous new world. The ability to understand folds per product and folds per hour led to new discoveries of ‘utilisation’ and ‘productivity’.

This soon led to modeling of new ideas and the first whispers of ‘daily production’. “What if we only folded what we needed for tomorrow?” These new radical ideas were met with some skepticism and mutters of “blasphemy” from some of the more old-school team members. It was too late however, the manager and the supervisor could not stop thinking about waste. It was as if the scales had been lifted from their eyes. They began to understand that the majority of their problems were coming from Overproduction. They even began to question if batching and large lot sizes were really as efficient as everyone said they were. They even started to discuss the forbidden lot size of one, but only where no one else could hear them.

They made an excel simulator and started testing radical scenarios using the data they had collected. Did they have enough capacity to try making only what was needed tomorrow? The number of setups would be insane, but was that a deal breaker? What would need to happen to make this possible? If they could pull this off, there would be no more need for folded stock in racking. Maybe the racking could be removed and the afternoon shift would be able to work in something other than perpetual twilight.

Layer Six

To achieve this, they would need to get others involved. The folded parts stock would become flat parts stock. Each part would need a sensible location, based on ease of pick and model rather than by part number. The two downstream departments would need an easy way to receive the parts, maybe some kind of trolley system? The supervisors of these areas were quickly recruited to the cause, delighted at the prospect of never having to get a stillage down from the racking again. There was much teamwork and collaboration of all from leaders to operators.

At last, it was all ready. The manager and the supervisor and the supply manager and the other supervisors were ready. All the team members were on board to at least give it a try. All the team members were skeptical and the folding team in particular were dreading all the set ups but they all agreed that it was worth it to never see one of the hundreds of stillages in the company again.

On that day, the folding system would forever be separated from the ROP system. From this day forward, the “Build Plan” would be their new deity.

Layer Seven

All was not well. The math had been correct, the numbers crunched. The consultation wide and varied. There was just one hundreds of little problems.

The system had been connected to itself, without safety stock between folding and the next areas. Suddenly, all the problems that had been hiding behind mountains of inventory were rising to the surface like a steel Zombie apocalypse.

There were always too many parts, or not enough. Quality problems were now stopping the production lines as operators could no longer, “just grab another one from stock.” Worse, the folder operators seemed incapable of counting. Making 20 parts exactly seemed beyond them. it was always 19 or 21. And then, there was…the rework….

There was nothing for it, the teams would have to start talking to each other, every day, every morning without fail. These problems had to be fixed and fast. The folding team was now a service to the downstream teams, a team that could not fail or they would stop the whole process.

Slowly, little by little, the teams resolved every issue between them until one day, the quickly constructed team board lay abandoned as there had been no problems for months. Whenever a problem did arise, team members just walked a few steps and got it resolved right there and then.

Happily Ever After?

Well of course not. But this is a blog post and not a novel and my fingers are getting tired. There is of course much more to the story. One day, I may tell you about how the manager and the supervisor convinced the scary wizard supply manager to let them control the sheet metal cut parts stock levels and make only to demand. You may also like to know how the great miscellaneous parts beast was captured, escaped and then captured again. For today though, we will let our heroes rest.

In short, the manager, the supervisor, the supply manager and all the other members of the kingdom company are still exploring and battling dragons learning and solving problems to this day.

Onion Improvement

Onion layer after onion layer has been peeled away and under each layer is a new skill set to be gained and new lessons to be learned. With every new layer that is exposed a new level of detail is required in order to be able to peel the next layer. It is never-ending and ongoing. Our eyes are constantly watering with the pungency of the fresh problems and learnings. We will never get to the final layer of our onion. Good thing we’re big fans. I especially like mine pickled.

But what was the point to this fascinating but somewhat long winded tale of adventure improvement?

The point, dear reader, is to not get discouraged by the overwhelming size of the problems in front of you or intimidated by the coolness of some other company. Just check out the timeline in the front cover of the great Taiichi Ohno’s Toyota Production System and you will see Toyota’s own onion being peeled. Everyone has their own onion to peel. Frankly, the method you use to peel it is not that important. In reality, the Toyota Production System (TPS) is just Ohno’s own story of peeling the Toyota onion.

Just start peeling your onion your way and the process will force you to evolve and learn at the right pace for you. Layer after layer, the process of improvement itself will require the right detail at the right time and targeted in the right place.

In the end, why would we ever do more than we need to right? Right?


  1. Yes, Lean is an onion. Peeling an onion makes one cry. I can assure any Make To Order manufacturer that embracing Lean as their manufacturing strategy will make them cry at how slow they achieved any success and at what great cost they achieved success. All for lack of wanting to learn what is way superior to Lean — Industrial Engineering.

    In fact, Lean is like the spoon that a Make To Order manufacturer uses to dig their own grave by relying on Lean as a manufacturing strategy.

    All being said, I only speak from personal experience, knowledge and implementation success with Job Shop Lean.

    Lean will make every high-mix low-volume manufacturer cry just as peeling an onion layer-by-layer will.

    Liked by 1 person

    • As always, your observations are astute. What lies beneath the layers of the onion are new and innovative industrial engineering techniques that help us solve the problems that Ohno never found in his own onion, while verifying many of things that he did. Thank you for commenting.


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