Today we’ll discuss the basics of Toyota's Takt Time and how to use it in actual operations.
[Intro Video]
Hi, this is Mike Negami, Lean Sigma Black Belt.
I made a video in the past about Production Leveling by measuring Cycle Time.
In Lean Sigma, there is another similar term: Takt Time.
Takt means ‘beat’ or ‘pace’ in German.
Takt Time is a word coined by Toyota and a method to make the whole factory work with
constant rhythm.
It’s the standard time for how fast a worker can make one thing or work on one unit.
It’s said that the speed should not be determined by the circumstances of the company, but by
the customer's needs.
The calculation formula is: Takt Time = working hours of a day ÷ the number of items that
can be sold in the day.
These working hours are pure working hours excluding waiting time and break time.
For example, if there are 8 working hours and quantity sold is 1000, 480 minutes (8
Hours) ÷ 1000 = the Takt Time of 28.8 seconds.
In other words, make one item every 28.8 seconds.
This is explained in various books and websites, but there’s not much written about how to
use this Takt Time in practice.
Let's learn how it’s used by Toyota, which created this method.
This is the Toyota Production System History page of Toyota's official website.
Here it says in the section of ‘Establishment of Standardized Work’, ‘In 1953, Toyota
established standard operations consisting of specified Takt Time, Working Sequences,
and Standard In-Process Stock.’
It means that they have set up standardized work for each workstation, but more importantly
they’ve decided on the rule to specify the three elements of ‘Takt Time, Working Sequences,
and Standard In-process Stock’ in setting all standardized work.
‘Standardized Work’ is really important.
Toyota has many famous tools and methods, but they cascade those effects to the frontlines
with this ‘Standardized Work’.
I’ll explain ‘Working Sequence’ first.
It is the same as SOP (Standard Operating Procedure).
The safest and most efficient work procedures should be written for each workstation.
It will increase labor quality.
‘Standard In-process Stock’ is the appropriate number of work-in-process stock each operator
can have.
The company should decide the numbers that are not too few nor too many for each workstation,
then this will help you to prevent inventory waste by making each operator maintain the
number closely.
Lastly, the main topic: ‘Takt Time’.
We discussed the company's overall Takt Time earlier, but since each workstation’s situation
is different, it’s necessary to configure the Takt Time for each workstation.
Theoretically, the calculation formula for the workstation is the same as overall Takt
Time.
You should refer to the calculation result, but the company should have the final call
to decide it.
Those workstations’ Takt Times become the standard work speeds for how fast to make
one item.
On the other hand, actual working time is called Cycle Time.
Here is the relationship between Takt Time and Cycle Time.
If Cycle Time is faster than Takt Time, inventory will increase, but if Cycle Time is slower,
becoming out of stock will occur.
Therefore, it is important to supervise the all operators work at a constant speed for
their Takt Time.
There is a saying “There is no improvement without standards”.
‘Standardized Work’ will set the standard for an entire business.
Especially by practicing Takt Time, you can make the whole factory work with constant
rhythm, reduce Mura, Muri, Muda, which are ‘Unevenness, Overburden and Waste’ and
achieve Heijunka, which is Product Leveling.
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