Kanban Flow as Nature Intended

Kanban is a signaling system, designed to trigger an action.  If you think about your experience, there are Kanban systems all around us – indeed, they might be so obvious that we miss them.  In this article we discuss a simple Kanban system, the 7 simplified principles of Kanban, and an everyday example from my own family – an example which you might be able to relate with.

A Kanban can come in many forms.  Some of you have seen the typical signboard Kanban, a walking alarm clock as an auidble Kanban to force you to awake, or an obvious signal Kanban from software development or manufacturing.

A Kanban can also be a “withdrawal kanban” or a “production kanban”.

• Withdrawal Kanban: Authorizes the movement of parts from one stage to the next stage.
• Production Kanban: Releases materials to the preceding or “upstream” step for replenishment of needed parts to produce.

They are closely related, but in this article we’ll highlight the withdrawal Kanban.

Regardles of Kanban format, a Kanban is designed to signal the following things:

1. Something is needed
2. What that something is
3. When it is needed
4. How much is needed
5. Who needs it and who needs to provide it
6. And some level of predictibility in the process – “operationalize the process” would be the business-speak for what we are talking about
7. Do not pass defects to the next stage – disrupts flow, causes defects, rework.

Given the elements of an effective Kanban above, one of the best natural Kanban systems is the cry of a baby.  Let’s investigate.

Infant as Natural Kanban

1. Food is needed
2. Milk is needed from Mom or Dad (if bottle feeding)
3. This is where things break down in our example.  Ideally, some lead time is signaled by the baby to the parents – maybe a 5-10 minute lead time prior to the all-out screaming cry for food.
4. Depending on the baby and doctor’s suggestions for feeding the baby milk in ounces
5. The baby needs to be fed by the caregiver – mom or dad
6. It has to be said – but do not feed the baby spoiled milk, or milk in a bottle that is not the right temperature of too hot or too cold – why?  Well, spoiled milk will harm the baby and if the baby is selective, they might not drink the milk if it is too hot or too cold for their liking.  Rework is the result of failing on the temperature requirement and panicky parents running about is an appropriate picture to have in your mind’s eye.  In business, this is aptly called “firefighting” – which is an overly-charitable term we give to ourselves in business.
7. The process is predictible – all humans and babies have to eat and, since babies have no “schedule”, they do have a routine and they are not shy about letting the caregivers know when they are hungry and need to be fed.

Flow and Pull

The scream of a hungry baby as Kanban wouldn’t work well if we fed milk to the baby through a firehose.  That approach is an extreme example of Push manufacturing – that is, producing more than is needed.

Imagine if we did do that.  What would happen?  The baby (which is our customer in this case) wouldn’t be satisfied.  And, the baby would dribble most of the milk and much would be wasted.  Rework would be the result, so the baby can be satisfied, exasperated parents because there was no “leveling” of demand, and a qualitative feeling that we didn’t do as well as we could have.

Back to natural Kanbans.

The baby bottle nipple, on the other hand, is a Pull mechanism.  It is designed to help the infant eat only what is needed.  Modern baby bottle nipples are designed as variable flow – which means that they can be adjusted to help the infant drink as much as they need at that time – no more, no less.

The result of all this is a natural Kanban that works incredibly well, with little to now waste.  The baby is satisfied, little milk is wasted, and the providers of what was needed (milk for the baby, provided by Mom or Dad or caregiver) know what is expected of them, when it is expected of them, and know how to provide what is needed.

It’s Your Turn

What other natural Kanban systems do you see around you?  How can you apply the principle of the Kanban to your professional life?