- What is kanban?
Well, it's many things a kanban is an object,
kanban is a set of principles,
Kanban is also an agile framework.
And in this video, we're gonna be looking
at all three aspects of kanban
with the help of a coffee machine,
a Doctor Who Lego character and a coffee cup.
Welcome to Development That Pays,
the number one agile channel on YouTube.
My name is Gary Straughan
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All right, before we go too much further,
let's disambiguate.
There's Kanban the Agile framework an alternative to Scrum.
I like to write kanban in that context,
with a capital K, an uppercase K,
but long before there was an uppercase K kanban,
there were a couple of lower case kanbans.
Kanban the thing, the object, the sign
and kanban the set of principles.
And today we're gonna start by talking about the latter two.
And then later we'll add the Kanban the framework
back in to the brew.
Talking of brew, I think I'm gonna grab myself a coffee.
Okay into the shop, I place my order,
tap my card, and she gets on and makes my coffee.
(coffee machine whirring)
Finally, I collect my coffee.
Did you see any kanban here?
No, neither did I.
For the simple reason that there really isn't any need
for any form of kanban in here.
And now it's probably a good time to introduce
a couple of terms that I'm gonna rely on later.
What we have here is a defined process.
Take my order, make my coffee and deliver it back to me.
And with just one person doing all of the steps
in that defined process, we really don't have any need
for any special orchestration,
other than the fact that those three steps
really should be done in just that order.
If the coffee shop becomes a bit of a destination
in the neighborhood, and of course, I wish it every success,
then it's gonna feel the need to scale things up a bit.
One option would be to just
well, instead of having one barista in the shop,
he could have two.
Each doing, well everything
and providing they can maneuver around each other.
There's not much we need to do, to make things work.
Still the same defined process
and the need for a little bit of orchestration,
but largely it takes care of itself.
The till is either available or it isn't
and the coffee machine is either available or it isn't.
Actually this fine looking machine
looks like it might be capable
of preparing more than one coffee at the same time.
So that's one option,
two people doing all of the steps
inside the defined process.
The coffee shop has another option for scaling things up,
and that is to begin to specialize.
Instead of adding a second barista,
they could choose to add a dedicated order taker.
I struggled to find a good Lego character.
This is apparently Doctor Who and yeah,
so Doctor Who is gonna have to do for yeah,
for the guy taking the order in the coffee shop.
So yes, Doctor Who taking orders, barista making the coffee
and this arrangement this specialization
comes with some notable advantages.
We have a dedicated order taker
who can presumably become better at order taking over time.
And we have a dedicated barista
who is focusing all of his attention
on becoming better at making coffee.
There are other advantages to this approach.
And if you can think of any, I'd love to hear from you
in those comments below.
Well I'm gonna go on now to talk about the disadvantages
of this move to specialization of skills.
And again, if you can think of any of the downsides
of working in this way then I would love to hear from you.
I am going to focus on just one of those downsides,
and that is that we now have added some complexity
to our process that wasn't there previously.
And that is our defined process now requires two people
to carry it out fully.
For the first time we're having to handle
the handoff between the person taking the order
and the person making the coffee.
Let's take a look at that in action.
Here's the coffee shop, let's bring in the barista.
And let's bring in you know who yeah,
yeah, that Doctor Who guy
and let's give them some customers to serve.
This person who's just arrived at the coffee shop
and joined the queue, that's our hero, his name is Robert.
And Robert patiently waits in the queue, ready to be served.
Okay, now he's at the front of the queue,
he's placing his order, coffee type, milk type,
and all of that information is recorded on the cup.
How interesting.
He's also asked for his name
and his name is also recorded on the cup.
Obviously, if this has been real life,
the writing wouldn't be nearly so neat
and the spelling would not have been nearly so accurate.
But this will do for our purposes here today.
This is interesting, Robert's just left one queue
and joined another.
We'll be talking more about in due course.
The barista's now ready to pick up Robert's cup.
He reads the information from the side of the cup,
so that he knows exactly what coffee to make,
gets on and makes the coffee.
(coffee machine whirring)
And finally, Robert is in receipt of the perfect brew.
And at that point, of course, he's able to leave the shop
and get on with his day, the process now complete.
Hopefully no surprises there,
that much is your experience
of how things tend to work in a coffee shop.
Now, big question for you.
Did you spot the kanban?
You're quite right, the kanban is actually the coffee cup.
This coffee cup kanban,
helps us with a couple of complexities that weren't there,
when we had one person doing everything
in the defined process.
Taking the order, making the coffee, delivering the coffee.
Now with two people in the mix,
we have the situation where the person,
who is making the coffee didn't take the order
therefore doesn't know what was ordered,
nor do they know who placed the order.
The kanban coffee cup answers both questions
all of the information needed to make the coffee
is on the cup and also the name of the person
who placed the order is also on the cup,
two problems solved.
But a kanban, coffee cup shape or otherwise,
does not a kanban system make, as we shall soon see.
I'm gonna give our friends here
just a little more breathing room.
So let's start by looking at things
from the point of view of the customer.
The best experience for our friend Robert
is that the cup barely touches down on the counter
before the barista picks it up to make his coffee
and then barely hits the desk on the other side
before Robert picks it up and goes off with it.
I'm sure you'll agree that the best experience for Robert
is to get his coffee through the entire system
in the shortest possible time.
Now let's go look at that process once again
but this time, I want you to pay a special attention
to the progress of the kanban, the coffee cup kanban
through the system and pay extra special attention
to the point where the kanban comes to a halt.
An order comes in, the details are written
on the kanban coffee cup
and the cup is placed on the counter to wait its turn.
Then another order comes in.
Then another order and then another,
then another order and then another.
All during the time when our friendly neighborhood barista
is busy making one perfect brew.
This stash of stationary cups, stationary kanbans,
means there's a corresponding queue of people,
not the first queue of people waiting to place an order,
the second queue of people
who have yet to receive the coffee.
Certainly not a desirable state of affairs
and there are lots of questions
I could ask you at this point,
but I'm gonna ask just one, whose fault is this?
I suppose we could point the finger of blame at the barista.
Perhaps he should be working faster.
But a perfect cup of joe cannot be rushed.
I mean, maybe we could shave 10% of his time,
while maintaining optimum coffee quality.
But that's gonna be nowhere near enough
to clear this backlog.
Perhaps then it's the order taker that's to blame
and in fact, our friend Doctor Who here
is perfectly positioned to prevent this pile up.
He could indeed realize that things are starting to unravel
and could start to stall, he could start
to take orders more slowly.
And this is kind of counterintuitive
that we should pay a specialist
and then asked him to do his best work by slowing down.
This is also a subject that we will be returning to,
in due course.
Have you by any chance heard
of the fundamental attribution error?
It is our human tendency, not a very good one either.
Our tendency when things go wrong,
to look for the guilty party to try to find a scapegoat.
And it's an error because in most cases,
the overwhelming majority of cases,
when things go wrong, it's not a person that's to blame,
it is the system.
I mention it now because I was, just guilty of it,
looking for someone to blame,
when really, it is the system that is to blame.
What we need to do here is fix the system
so that this pile of cups cannot happen.
And we can do it very simply,
just by applying a hard limit to the number of cups
that are allowed in this area at any one time.
By the way, we've just implemented a kanban principle,
the principle of limiting work in progress of a system.
What we've also seen, we've glimpsed,
we've been given a clue as to the true nature
of a kanban, that's kanban the object.
Our kanban coffee cup represents a request
to do something specific.
To prepare a coffee to Robert's specifications.
But it also represents a request to do something in general,
to introduce another coffee cup into the system.
The value of a kanban isn't just in its existence,
it's also in its scarcity.
And here we can draw a parallel between kanban and currency.
A dollar bill doesn't have much intrinsic value.
I mean, it's kind of a bit of paper
with some clever printing on it.
The value of a dollar bill, or a pound coin or a euro,
comes from the fact that the supply is limited.
So it can be said that kanban isn't really about the cards,
the tokens, the coffee cups,
in the same way as currency isn't really about the notes
and the coins.
At this point, you might be thinking,
I could really use a cup of coffee.
You might also be thinking that this here,
coffee shop example is all very well and good,
but how does it relate to my kanban board?
How does it relate to Kanaban with a capital K,
Kanban the Agile framework.
We are gonna be getting into that
and talking more about those kanbans with a little K
in the very next episode.
I look forward to seeing you then.