Imagine you are planning to take a trip. But you notice the gas light is on. What do you do? You go to the gas station and fill up the tank before you run out of gas.
If you think about it, you’ll notice that you are completing a task only when there is a need to, when you receive a signal. Which means you are part of a pull system.
But what does it mean to use a Kanban pull system in your work environment? How does it work?
What is a Pull System?
The pull system dates back to the 1940s as part of the lean manufacturing principles. The purpose of a lean pull system is to create workflow by pulling work in only if there is a demand for it.
Being a lean manufacturing technique, the pull system is a production or service oriented process used to reduce waste. Using a pull system allows you to begin new work only when there is either customer demand for it or goods are required by the next step within the production process.
Relying on demand helps you to accurately determine everything. From the materials necessary for future production, the number of people needed to complete the job, to the terms of delivery. This way, you can reduce overhead and optimize storage costs. The pull system is also known as built to order production or inventory system. Furthermore, the pull system will allow you to deliver just in time.
Implementing a Pull System with Kanban
The Kanban methodology is a lean project management methodology in its core. It advocates taking on new work only when there is capacity for it. In fact, Kanban is the oldest and most widely spread method for applying a pull system. The pull system uses two main components – visual signals and upper inventory limits. In Kanban, we have the Kanban cards and the WIP limits. So it’s no wonder why Kanban is perfect for running a pull system.
Additionally, Kanban is based on a set of principles and practices that are easy to understand. Implementing them is also fairly simple since you do not need to make any serious changes to your existing process. But it is key that you understand the methodology and stick with the core practices if you want to successfully implement a Kanban pull system.
When applying a Kanban pull system to your organization’s process, follow these 3 key steps:
Visualize Your Process
Applying Kanban begins with the visualization of the workflow. It’s the foundation of Kanban and a vital part of keeping the pull system efficient. The process needs to be mapped out as accurately as possible. Feel free to go beyond the default 3-column setup, To Do, In Progress, and Done. Add columns and swim lanes for each step of the process and determine the steps in each stage. This will allow you to get a comprehensive view of the workflow and help you spot problems.
Move from Push to Pull
Now that your boards are set up, you need to change the way you add new tasks. Instead of pushing new work to the team, establish a pull process and take on new work only when there is demand for it. That way, you will be able to increase the efficiency of your team, and the process and reduce cycle times. You will produce only work that has value to the next step of the process and lower inventory costs. Ultimately, you will deliver value to your customers just in the right time.
Set up WIP Limits
The last step in setting up a Kanban pull system is defining work in progress limits. You have analyzed the process and limit the amount of work that enters and exits the workflow. The speed at which items are moving through the board should be balanced so you don’t clog the process. You can set global WIP limits or limits for each column. The role of WIP limits is to reduce lead times and make the flow run smoothly.
Running a Kanban Pull System
Once the Kanban pull system is in place, you need to carefully manage the process and apply another key lean management principle – continuous improvement. Since the process is a live matter, always moving, you must keep a watchful eye on it. It’s crucial that you quickly notice areas that need adjustments and implement the changes immediately.
Monitor the board and try to identify areas that can be further broken down, or tasks that should go through more stages to make cycle times shorter. This way, the team can focus on smaller chunks of work, and pull cards from one stage to another faster, keeping the process moving at all times.
It’s also important to make sure the pull signals are in place. To help the team adjust to the new Kanban pull system, you can add an additional review column after each specific activity. This step will not only serve as a signal that the items are ready to move to the next stage, but will also increase the quality of the work you deliver.
Last but not least, is the identification of bottlenecks which stem from the difference in capacity of each stage in the workflow. Luckily, if you visualize your process on the Kanban board as accurately as possible, you should recognize any impediments at first sight. When you notice that a specific stage is becoming a bottleneck, you should go straight to investigating the root cause of the problem. Next, take proper actions to remove the bottleneck and make adjustments to your workflow.
The Kanban pull system is stable and suitable for application in almost any production system. It offers numerous benefits such as an increase in efficiency and delivering work faster, reducing waste and improving the workflow. Additionally, the Kanban pull systems allows you to collect historical data about the workflow and average cycle times. Thus, you can make more accurate plans and predictions for your future work.
While pull systems were traditionally used in manufacturing, we now see the application almost everywhere – in software, healthcare, data processing. The only requirement for a Kanban pull system to work successfully is to control the number of tasks or parts that are arriving.