First, here is what we know about Kanban:
- Not a process itself.
- Supports a pull based system.
- Enables visualization of work through a value stream.
- Visualization enables measurement, which enables Kaizen (reducing waste).
- Waste is downtime in the value stream.
Being a person who is either impatient, or who values efficiency - one activity that I recognize could use Kanban is the deli counter at a supermarket. I'll take a stab at applying Kanban and suggest how it might improve the process.
If you visit a supermarket deli, typically you would take a number and wait around for the next worker to help you with your order. You'll be asked what you need and they'll keep it in their head and usually have to ask a few times per order item to clarify. Most deli counters will take you a sample and ask if the thickness is ok. Perhaps they will work on one thing at a time and ask again what's next after each one until your transaction is complete.
If we introduce Kanban into this system, the first thing we need are order cards and customer cards. The orders would come in from the customer on an order card. This would contain information about each order item - item type, brand, quantity, thickness, etc. The order card would be taken by the worker one at a time and the customer would receive a corresponding card with a number on it. When the order is ready, it is delivered to the customer at the counter, the customer exchanges their numbered card for their order items.
But wait, I'm sort of getting ahead of myself here. We should not change the process just yet, but only use kanban cards to represent exchanges of information and goods in the current process. Let's try again -
First - customer grabs number kanban and waits until number is called. Once number is called, customer gives number to worker.
Worker passes customer an order kanban for the first item and a kanban for a sample. Customer gives worker first order item kanban and an order item sample kanban. Worker makes a slice of the first order item and exchanges it for the sample kanban. Now the customer either approves of the order, or declines and either changes the order or leaves.
If the customer approves (we'll look only at the happy path for sake of brevity), then the worker completes the order item. Once the item is complete, it is exchanged for the order item kanban. If the customer wants anything else, repeat.
It's easy for us to see that there are multiple opportunities for waste in this process. This is evident because the number of transitions at best are 5n + 2 where n is the number of items. For three items there would be at least 17 transitions. The number of times between transitions that the customer is idle are 2n + 1. The worker is never idle, however they are wasting a lot in transitioning.
One improvement would be to have the customer place the whole order, then pick it up later after they've had a chance to shop for other items in the store. Or the customer can have the whole order on some card with standard thicknesses and indicate whether or not they want a sample. There can be special instructions if needed. This would reduce waste by the worker and reduce lead time (where the customer is waiting).
In an even better world, where Kaizen and Just in Time is valued even more, the customer would receive their order JIT as they are checking out! I would suggest placing the deli between the registers and entrance. Customers would stop by the Deli, get samples and place their order. When checking out, the deli items would be paid for by the customer, then delivered JIT bagged and ready to go into their cart along with other items.
This example serves to show how Kanban and other principles of TPS can be used to improve existence - no more wasting time at the deli counter. But this can be used to improve development processes as well as other IT processes. Wonder if it could improve the lead time on government initiatives?