Kanban is a Japanese word by which a Lean Production technique is commonly referred to.
In particular, the aim of kanban is to avoid overproduction, which is the waste that has the greatest impact on the performance of a production system.
It appears to be an ‘innovation’ methodology but, as is often the case, theory often loses strength in practice. And this is what we believe has happened with the Kanban method.
To stimulate you in this reasoning, we propose the same questions we have asked ourselves:
do you know suppliers who offer something at zero cost on a repeated basis over time?
would you entrust a single supplier with all purchases for your company, aware of the risks involved?
would you give a delivery man access to the cupboards in your house, allowing him to fill them with pasta, jam and fruit if necessary?
We are aware that, for those who know their way around the practical world, these are rhetorical questions, just as we are aware that the last question is (deliberately) pushed to excess.
In our eyes, it remains evident that this method does not serve the interests of the customer in any way.
One clarification: we speak of the Kanban method in relation to our experience and our production reality.
Although we produce fastening systems, we are well aware that fasteners are a category C product.
To put it more clearly, here is a ‘nice’ comparison: vitaria is as valuable as toilet paper.
Little things considered useless, but which would be a problem if they were not there
Yes, it makes one smile, but it is a very important topic.
The ancillary service to these ‘C-categories’ (around the grapevine) includes facilities, technologies, pushes, ad hoc management programmes and the employment of significant personnel… all of this often costs more than the grapevine itself.
All the disadvantages of the Kanban method according to Kilton
Here are some of our thoughts/advantages regarding the Kanban method:
- binding contracts with parameterised cost increases
- loss of contact with vendors
- confusion in the internal organisation of work
- extra and unnecessary costs for warehouse facilities
- less resilience to line stop and warehouse distribution
- personnel from outside the company
- system too complex and non-functional
- professionals to specialise only in Kanban
Binding contracts with parameterised cost increases
The contracts that are concluded with Kanban bind two to five years minimum, with a parameterised increase independent of market trends.
This is why many companies found themselves subjected to contractual increases despite the period of material depreciation.
Not only that, some had to undergo increases in order to receive the supply.
Failure to consider the ways in which the market can fluctuate and become constrained over the years is now a huge risk of loss
Loss of contact with vendors
It may have happened that some suppliers, after learning that you are under Kanban, no longer visited you or contacted you to propose new products.
Did you ask yourself why?
The answer is simple: because you are already under contract and the suppliers know that they will not be able to sell you their goods for some time, probably years.
It is true that this may mean fewer phone calls, fewer e-mails and less spam, but there is a huge tailspin that you do not consider: you are losing knowledge of market trends.
You are out of the news and no longer have price references.
ConfConfusion in internal work organisation
With Kanban, all a warehouse worker has to do is frame a QR-code, type in some information on his mobile phone and the goods arrive in the right quantity to fill the box.
What’s the problem? The problem is that that person is doing the work of a supplier.
He uses his portal, uploads the order to his system and into our management system.
In fact, it is working once too often.
With Kanban, you no longer pay employees to pick up the phone and request a product, but you pay them to handle two separate operations.
Extra and unnecessary costs for warehouse facilities
In some cases, Kanban requires the installation of special structures in which each box is equipped with a weight sensor and a transmitter.
These are obviously not free.
Returning to rhetorical questions, does it make sense to rent a car for 365 days a year and end up paying more for that rental than a car you own? Absolutely not.
The icing on the cake is the fact that if the contract with Kanban is not renewed, everything will be taken away. And you will have to start from scratch with new programmes, new implementations on your management system, new procedures etc etc.
Lower resilience to power and distribution line stop
Another disadvantage we noticed was the lower resilience to power line interruption.
The mandatory lockdown period that came with Covid-19 made this obvious: when the lockdown was coming to an end, the supply line suffered long delays in being re-established.
The first interrupted input also interrupted everything else, in a cascading effect.
These delays and the interruption of production were aggravated and extended throughout the entire supply line.
Here’s a ‘practical’ example: if someone brakes on the motorway, the cars behind also brake.
And those behind brake again In the kilometres further back there will be no more cars braking, but there will be a queue directly.
Outsiders in the company: a privacy and security issue
When you choose Kanban, you agree to host external personnel in the company.
From the perspective of corporate privacy, this can be a huge problem for some.
This is not a question of trust, our point is another: what would happen if a figure from another company, albeit an authorised one, were to get hurt?
What are the implications?
As a matter of fact, the company also supplies the personnel working for your company at that time
One has to be very careful in this respect: privacy and security are strongly at risk.
System too complex and non-functional
Kanban is a complex and overly detailed system that cannot be learnt or implemented in an hour.
The people involved often do not fully understand what it is all about and this is its weakness.
In other words, a functioning and functional system must have among its characteristics that of being easily learnable.
Furthermore, Kanban does not allow for sudden reversals or drastic changes.
If a customer wants to cancel a product or, on the other hand, wants to double the quantity … nothing can be done. Let us not forget that Kanban works if the numbers you have programmed with the supplier are exact.
The system is already in place and it is easy to change it, but only theoretically or on standardised products
Therefore, the system works in relatively stable environments where few changes occur.
However, it is confusing in dynamic environments with varying priorities.
Professionals to specialise only for Kanban, other costs
With the Kanban method, everything depends on the work teams: those with less experience, those who know each other less and those who are less disciplined always end up with more problems.
And here again we ask ourselves: does it take a highly specialised, experienced and team-oriented group of people to make Kanban work?
The costs rise.
In the production environment, you need qualified personnel who know how to manage and respect a pyramid control scheme.
It is necessary to check that the production meets the work demands, that team members are not inoperative, that there are not too many people on one step and that the right priorities are being respected.
Things that are done in any manufacturing company, but which Kanban seems to require in an even more extreme way.
To summarise, does it make sense to focus on claimed savings through the use of Kanban, if the basis still requires very specific and very expensive technologies and personnel choices?
Conclusions on the Kanban method
To sum up, where others see a functioning system, we see a system where task and responsibility relief reign supreme.
For us, it is a system where the customer is at the mercy of a supplier.
When this happens, there is certainly no saving or progress.
It is undeniable that it is a service and that like all services you pay.
But how much should you pay to actually have a service that is secure, efficient, respects privacy and responds promptly to every need?
Too much compared to the gain.
A Kilton episode on the Kanban experience
Here we report the experience of a former customer who, not knowing who to call to procure screws, contacted us again after eight years of Kanban.
“My old suppliers are hesitant towards me, they ask me why I am coming back after years.
I’m left without the person who manages the screws, so I don’t know where and from whom to get them.
You were right in advising me to avoid this system”.
At the end, he asks us whether we also use the Kanban method
To our negative answer, his conclusion is:
“That’s too bad, because having dismantled the shelf structures and having no more references, I have to use this system.
Having reached this point, we can only reply: the warnings were there.