You are here in your Lean journey:


Have you ever been to a traffic jam? Most likely, yes.

In a traffic jam, there are all kinds of things keeping you from moving: too many cars trying to move at the same time, traffic lights, speed limits, sometimes accidents, sometimes potholes along the way, and so on.

On the other hand, when you’re in a free highway with no obstacles, nothing can stop you: with every car moving freely and smoothly, the path is clear, no car is blocking your way and you barely have to stop. 

That is flow.

FLOW: the state of a process in which the parts move from one step to the other in a steady, continuous stream, as quickly as possible, without compromising quality.

And once you identify what are the obstacles in your process and where to find them, you are ready to let all of that go where it should go: away.


Remember TPS, the Toyota Production System, that laid the foundations of Lean?

It exposes the three villains that make processes inefficient and keep organizations from delivering more value.

And it’s about them that we’ll talk now, so get ready to learn some Japanese words! Here are the 3Ms of Lean:



This word means unevenness, variation, irregularity.

Remember our highway? The traffic in it will be much different if you take it on a regular day than if you take it in Christmas, right?

Roads are full of variations. On a regular Tuesday afternoon, they might be almost empty. The Highway Patrol might even be out of work to do. On the other hand, on the holidays there is a higher volume of people driving. That means more accidents, more broken cars by the roadside and more traffic jams.


That is Mura. In the Lean universe, Mura is the inconsistencies in the process. Everything that is not regular, that strays from the pattern. It can create fluctuations in production and make employees work too much or too little, for example.

Which takes us to the next M:


This word means overburden.

Can you imagine what it’s like to be on the Holidays shift of the Highway Patrol?

With the number of drivers, cars, accidents and traffic jams, the officers and the whole system have a lot more work than they normally do. They become overburdened. 

This is Muri, and it can mean the overburden of both equipment and people in an organization.


Muri gives unnecessary stress to employees and processes and can have many causes. One of them is our old pal Mura. If there’s unevenness in a process, it’s very likely that somebody – or something – will be overburdened. 

Overburden can also be created by lack of training, use of wrong tools or unclear ways of working.


This word means uselessness, wastefulness, futility

This M you already know: it’s our old enemy waste.

As mentioned before, waste comes in all shapes and sizes. 

In Lean, we talk about 7 kinds of waste. Here they are with some examples:

  1. Transport: moving materials, documents or pieces from one place to another
  2. Inventory: purchasing online tools that people rarely use or more office supplies than necessary
  3. Motion: hosting meetings that could have been an email, badly structured workspaces
  4. Waiting: waiting for an approval from higher management, waiting for work to arrive to you
  5. Overproduction: launching features nobody needed, filling in too many documents
  6. Overprocessing: spending too long on a given task, having multiple levels of approval for small tasks
  7. Rework (Defects): bugs, incorrect collection of data



By now, you have probably noticed that having one of the Ms will most likely yield the others, too.

When Mura (unevenness) is not reduced, there’s no scape to Muri (overburden) and to Muda (generating waste).


So the way to attack them is to reduce them all at the same time.



Do you know when you’re at an event and you want to go to the bathroom, but the line just keeps getting longer because somebody is taking too long? That person is the bottleneck of the bathroom-going process.

Bottlenecks are one of the reasons why projects get delayed, processes become unpredictable and resources are wasted. They also keep companies from creating flow.

Usually, the step of the process in which the bottleneck exists is the one that takes the longest to be over. That is because bottlenecks are like viruses. They install themselves in the process and take control of its timing. They harm its efficiency that’s why it’s so important to find them and eliminate them. In this article, you can learn more about that.

BOTTLENECK:a piece of equipment, a person, a department or anything that blocks a process and keeps it from running smoothly


Hey, no one expects you to simply guess if you have generated Mura, Muri or Muda. And no one expects you to simply guess where your bottlenecks are.

Since they all can be hidden, it’s important that you are looking at the right metrics in order to find what could be improved in your value-creation process.

So here are the most important metrics for you to keep an eye on:


Takt is a German word that means rhythm or drum-beat.

So this is the metric that will help you measure what is your production rhythm based on customer demand.

The Takt Time is the relation between the time available to meet the demand and the amount of demand you get. Like this:

TAKT TIME = available amount of time / existing demand

So if, for example, a chef works 8 hours (480 minutes) a day and receives 20 orders on a given day, their Takt Time would be:

TAKT TIME = 480 minutes / 20 orders = 1 happy, fed customer every 24 minutes


This is the metric that tells you how long it takes to complete one activity from beginning to end. This includes any waiting or delay that may happen during it.

This is something you can measure even by using a stopwatch. I can measure that it takes the chef an average of 16 minutes to make a dish, for example. That is the Cycle Time.

You can also calculate it using this formula:

CYCLE TIME = available amount of time / how much can be produced in such time

So in the case of our chef, it would be something like this:

CYCLE TIME = 480 minutes / 30 dishes = 1 dish coming out every 16 minutes


It’s easy to confuse Takt Time with Cycle Time, so remember: Takt Time depends directly on customer demand, while Cycle Time is based on the process itself.


The Lead Time tells you how long it takes for the customer to get what he ordered. This counting starts when the order is made (not when its production actually starts) and finishes only when they receive what they ordered.

This means that here you will count the Cycle time (the actual production time) + every other step, like transportation, payment etc.

LEAD TIME = time from order received to order delivered


So in our restaurant, the chef might take 16 minutes to make a dish. But before that it took 10 minutes for the person to choose and order, then 30 more minutes for the person to eat and 5 more minutes for them to pay.

The Lead time would be:

LEAD TIME = 10 + 16 + 30 + 5 = 61 minutes


Managers usually care more about the Cycle Time, but customers care about the Lead Time. That means managers should care about both.


Once you know your Takt Time, your Cycle Time and your Lead Time, you’ll be able to monitor if they are going up or down. And if they are, you can investigate why and correct the problems you find.

Spoiler alert: they will probably have something to do with the 3Ms.



Imagine that you need to send a welcome email to every customer that signs up to use your software.

If you have an employee responsible for doing this manually, there will likely be typos in the email, it might contain incorrect information about the customer or it might not even be sent because that customer was accidentally skipped. 

Now if you automate those emails, you will most likely reduce the chances of human mistakes. And the time of that employee can be used for more important things, like making sure the work is running smoothly, and detecting and correcting any eventual flaws that may appear from abnormal conditions. And, as a bonus, this person will also be able to take care of more processes at the same time. 

That puts way more quality into what you are delivering. And that is what Jidoka is about.

JIDOKA: an adapted Japanese word that means autonomation (autonomy + automation). It represents the automation with a human touch.


To automate parts of a process or even a whole process is a great way to reduce the chances of bottlenecks and to create flow. And things get even better if you are able to ally the wonders of automation with the awesome human capacity to solve problems (learn more Lean + automation here). 

The idea with Jidoka is to have a clear view of the causes of those problems and stop work immediately to solve them so that they never occur again. This leads to improvements in the processes and higher quality in the delivery since you will be eliminating the root causes of defects once and for all.

That’s why Jidoka is one of the pillars of the Toyota Production System (TPS).

In a nutshell, the steps here are:

  • Automatically detect the flaw or the abnormality
  • Stop the workflow
  • Immediately fix the problem
  • Investigate the root cause of the problem (we’ll talk more about that in Chapter 5) and establish effective action for that problem to never occur again

So now that you got your process flowing as smoothly as a river, it’s time for you to start putting your energy and resources in making and delivering what the customer wants, when they want it and just as much as they want it. It’s time for you to establish a Pull System.



  • Creating Flow is an important part of Lean Management.  It is making sure that your process runs smoothly in a continuous stream, as quickly as possible and with no compromise to quality
  • You should be fighting the 3Ms as if the organization’s life depended on it. Because it does. Reduce unevennesses, make sure no one and nothing is overburden and get rid of all kinds of waste
  • Bottlenecks will slow down your process and kill your productivity. So make sure you identify them quickly and destroy them as soon as they appear
  • To do so, watch your Takt Time, your Cycle Time and your Lead Time closely so that you can identify anything that’s out of the expected
  • Find opportunities to automate tasks and processes and use human skills to correct mistakes quickly, making sure they won’t happen again