3. CREATING FLOW
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.
3Ms: THE PLAGUES YOU’RE GETTING RID OF
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:
DON’T GUESS, KNOW.
MEET THE KEY METRICS OF LEAN
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.
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.
WHY THESE METRICS MATTER
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.
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
BEFORE YOU GO ON: IMPORTANT THINGS TO REMEMBER ABOUT CREATING FLOW
- 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