On top of self checkout kiosks in grocery stores is a small light that changes between a couple colors. When a line is open and ready to use, the light is usually a soft yellow. When a guest is having problems with the kiosk, it changes to a blinking red alert to notify the attendant of an issue. That light is a kanban.
Kanbans are signals used to alert someone that attention (and likely action) is required, convey information, or communicate non-verbally for other purposes. Kanbans are another tool from Toyota’s pull based manufacturing system. Originally, physical cards acted as representation for the need of an engine component, and were passed to the relevant department when a new component was needed. If you made the steering wheels in your department, you would wait for a kanban card to show up requesting a steering wheel before making one. As part of Toyota’s Just-in-time delivery system, the manufacturers would only make a product when they received a card. Doing so prevented excess items from being produced. Over time, the physical cards were upgraded to digital signals that can come in the forms of colored lights, sounds, or other notifications.
Kanbans are all around us. The red notification bell on social media is a kanban that alerts you to check what happened. In our homes, we use visual cues to push us into action. When do you know to buy more toilet paper? Chances are you have a small supply in your bathroom, and when your supply reaches a certain level, you buy more. Same goes for salt and pepper – we buy more when we see that the current level is low. When do you fill your gas tank (or charge your battery)? Only after the gauge shows a low level of fuel (or battery life). Kanbans are a simple, effective way to communicate non-verbally.
A kanban can be a light, a physical piece of paper, an empty bin, a colored flag, or anything else that represents a particular action. In tech companies, kanban boards are often used to plan out a week’s worth of work. Different tasks are written down on sticky notes (or digital sticky notes), and employees grab one note at a time to work on that particular assignment and make sure two people aren’t doing the same work (advanced teams color coordinate notes to team members). The sticky notes are high level indicators of work to be done, not detailed instructions. In your own business, using signals to alert someone that a particular job needs doing ensures the right work is getting done on time. One example might be a red light means the manager is needed, while a blue light means that a customer service team member is needed. Additionally, kanbans are often seen in restaurants as a way to alert service staff that food or drinks are ready to be picked up and delivered to a customer. The kitchen staff will turn on a light, or maybe use a vibrating pager to send a signal to the right people.
Most companies likely have a couple systems like this in place already, whether intentional or not. In information heavy industries, inside of email inboxes, there are often flagging systems that attempt to alert users to the most important emails. The flag is a kanban to guide a user to taking action. (note, the email itself is not a kanban because it is written communication. Kanbans are intended to only be a signal or short blurb, not a whole message.)
To implement a new kanban in your company, start by identifying one area where they would be useful. Define the goals and set a simple measuring system to pay attention to. Don’t go too big right away. Lead with the most basic option that will work (e.g. colored sticky notes). Define the particular sets of actions that correspond to the signals and go over them with your team (or whoever will be involved). Test the new system for 30-50 reps and then evaluate how it’s doing relative to the previous way. If the process is smoother, great! If not, go back to the beginning, rinse and repeat.