Kanban Workflow – How does Kanban Pull System Work?
Step 1. Visualize your Workflow
- Identify work stages and the work items.
- Work items: The max effort of 2 days to keep it short and moving.
- Write work items on cards and stick them in columns, under corresponding work stages, based on system workflow – From left to right.
- Workflow can be depicted physically or with a tool like Jira.
- Sample Work stages: Design, Development, Test, Production, Deployment, Done.
- Each Stage can be split into- Ready and In Progress.
- Initially, these two sub-stages may not be present.
- Later they are introduced to check the waiting time in each stage.
Step 2. Establish a Pull System
Kanban Pull System
- Rather than pushing tasks into the process, teams pull work only when there is a need for it and they have the capacity to meet it. ‘In progress (IP)’ and ‘Done’ columns appear in every process state.
- For example, when a development task is finished, it is moved to the ‘Development (Done)’ column.
- Queue statuses are what ‘Done’ columns are referred to be. No one works on tasks in the queue states; hence these are passive.
- In our example, ‘Development (Done)’, is the queue from which testing teams pull tasks ready for testing once they have the capacity to handle new work.
- Teams can avoid multitasking by pulling work and focusing on the most important tasks.
- This results in higher throughput and shorter cycle times, which implies happy customers and higher profits.
Step 3. Limiting WIP
Create a Pull system upstream by setting WIP limits, and also ensure that the team “Stops beginning and Starts Finishing.” After finishing a task in the current stage, team members can pull a task from the previous stage, thereby freeing up capacity in the preceding stage. This keeps going till the input of the bugs/ tickets.
- WIP limits could be set based on historical data and capacity planning.
- In case many tickets get piled up in one stage other team members help their team members so that tickets movement is smooth, thereby increasing collaboration.
- WIP limits defined could be observed for 3 to 4 weeks and updated based on the team’s experience.
The sample Kanban board with WIP limits introduced is given below:
Sample Kanban Board with WIP Limits
Let us understand setting up a WIP limit for a phase in Bug-fix lifecycle with an example:
Project ABC is a maintenance project with a Bug fix in scope. This project needs to set up a Kanban board with WIP limits for the flow of Bug fixes. Let us try to understand how WIP limits are set for the Impact Analysis phase.
- History data says the team is spending an average of 4 hours on impact analysis.
- There are 2 designers working in the Impact analysis phase.
- They are allocated to this project for 5 hours a day.
- The capacity for this phase is 10 hours (5*2: No of hours * No of resources).
- Hence WIP limit should be 2 for the Impact Analysis phase.
Similarly compute WIP limits for Development, Testing phases. As a preferred rule WIP limit should not be more than the number of people working on the stage.
Illustration of WIP limits
In case the WIP limit is breached one could record them as well on the board and provide permissible limits for breaches. In case the WIP limit is breached more than the limit set, WIP limits could be re-computed.
Kanban board can include Blocked tickets information also. WIP limit should be computed based on the project’s context.
Step 4. Apply Pull Signals
The use of pull signals to indicate that fresh tasks are ready to be handled is an important part of a pull system. When the quantity of cards in a column falls below the specified limit in a Kanban pull system, a pull signal is generated. This tells the previous column that a new job is ready to move forward. No further tasks may be pulled once the work in progress limit has been reached unless an outstanding one has been completed first. This helps to avoid team burnout by ensuring that they only have as much work as they can handle. It also aids in the avoidance of jobs being overlooked.
Kanban – Agile Methodology
Kanban is a popular Agile Software Development Methodology. It is a signaling device that instructs the moving of parts in a ‘pull’ production system, developed as part of the TPS (Toyota Production System). Kanban is about envisioning the existing workflow in terms of steps. These steps can be created on the whiteboard.
Table of Content
- What is kanban?
- When Would The Kanban Approach Be Needed?
- Kanban Board/Card
- Principles of Kanban
- Kanban Practices
- Kanban Workflow – How does Kanban Pull System Work?
- Lead Time and Cycle Time
- Cumulative Flow Diagram
- How to Calculate Lead Time and Cycle Time
- Steps of Kanban Approach
- Benefits of using Kanban Framework
- Kanban vs Scrum
- Conclusion
- Frequently Asked Questions on Kanban – Agile Methodology
The main aim of Kanban is to reduce WIP (Work-In-Progress), or inventory, between processes by ensuring the upstream process creates parts as long as its downstream process needs it. The goal of the Kanban execution is to ensure work items move to the next steps quickly to realize business value faster.