The goal of every organization or team is to achieve a higher level of productivity along with superior quality products and services. One particular method that has been gaining traction in several industries is the Kanban system. Before we get to the formal definition of Kanban , let’s have a look at its interesting origin.
The roots of Kanban
In 1603, as Japan entered a period of stability, the economy of the country flourished. The streets were crowded with shop owners and local businesses, all eyeing to attract customers to their shops. It was on these streets where the term “kanban” first originated.
“Kan” in Japanese means sign and “ban” refers to board. Thus, kanban referred to the use of sign boards outside these shops to attract customers and communicate about the services offered. All the signboards used by the shop owners had one thing in common. The message was communicated clearly and in a concise manner.
The Toyota production system
The history of Kanban is associated with Toyota, where Taiichi Ohno, known as the father of Toyota Production system pioneered the Kanban system. Ohno recognized the inefficiencies in the production line and looked for ways to improve their processes. A car manufacturing unit requires approximately 30000 parts and components moving through the assembly line.Ohno observed the low levels of productivity and unnecessary inventory were hampering their efficiency and decided to solve the problem.
The supermarket concept
Taiichi Ohno took the foundation of the Kanban system from the operation of a Supermarket. Our visit to a supermarket can be summed up in the following steps:
- We check upon our stuff at home and schedule a visit to the supermarket when we realize that we are running low on stock.
- We then go to the store and get the desired stock from the grocery shelves.
- The supermarket crew replenishes the shelves when they start running low . This is to ensure the product availability for the next customers.
- Visual signals such as a depleting stock at home or empty supermarket shelf force people to pull from preceding processes.
In Toyota, they adapted the supermarket’s stock concept to improve efficiency. This concept helped line workers recognize at what time and in what quantity certain parts need to be prepared and transported. The person in charge of the preceding process, which is making the parts ready, supplies the parts to the next process when they need it and only in the amount needed.At the shop floor, workers used visual signals in the form of cards to signal their need for a component. And this is where Kanban goes into play.
Kanban can be defined as a visual workflow management system. It is used to keep track of work as it moves through a process. It is a means to design, manage, and improve flow systems for knowledge work. Kanban is one methodology that seeks to attain JIT inventory.
6 core Kanban practices:
- Visualize the workflow: This is the first step which aims to model the flow of work in a visual format. Kanban boards, kanban cards, columns and swimlanes are used to achieve the visuulization.
- Limit W-I-P -One of Kanban’s primary functions is to have a limit on the number of W-I-P items. If there are no such limits, we are not implementing Kanban.
Limiting WIP means implementing a pull system on the workflow or parts of it. Fixing limits per stage ensures that a card is only “pulled” into the next step when there is available capacity. Having such constraints will quickly highlight the problems in the current workflow which can then be resolved
3. Measure & Manage Flow– When we talk of managing the flow in kanban, we mean the management of the work but not the people. By flow, we mean the movement of work through the production process.A Kanban system helps you manage flow by highlighting the various stages of the workflow and the status of work in each stage.
4. Make Process Policies Explicit – The work process should be clearly defined and published. Every team and member should have a clear understanding on how the work is to be performed and the expected output from each process. These policies also serve as a checklist to ensure consistency and quality in the work performed.
5. Implement feedback loops– Having feedback loops are an integral part of a good kanban system.They supplement agile teams in becoming more agile.These feedback loops ensure that the teams are responding adequately to potential changes and enables knowledge transfer between stakeholders.A daily stand up of 10-15 mins, where the team members stand in front of the board and have have a short discussion is an example of a feedback system.
6. Use models and scientific techniques to improve collaboratively – Teams should strive to achieve continuous improvement through analysis of the current process and identifying areas of opportunity.Techniques like value stream mapping, which help teams to identify the value addition activities and remove the wasteful activities should be used in the kanban system.