Many development teams use the Kanban Method to manage their work. Kanban, like Scrum, is (fairly) easy to understand, but can be difficult to master. Getting the fundamentals right can help teams create alignment through visualization and to deliver maximum value in shorter lead times and at less cost.
Kanban Core Practices
Kanban is a WIP-limited pull system, the primary goal of which is to optimize the flow of work through a system in order to maximize the flow of value to a customer. Kanban has three fundamental rules: make the workflow visible to the entire team and limit work in progress to the capacity of the people who are doing the work. Then, measure and continuously improve the system to improve the flow of value to the customer.
- Visualize the workflow. This involves laying out the work on a board with cards representing work items arranged in columns that represent steps in a workflow. This provides clarity and helps teams understand how the work is actually done in a step-by-step way to provide the product or service to a customer.
- Manage Work-In-Progress (WIP) by setting limits on the number of work items in each workflow state. This ensures that work is pulled into each stage of the process only when there is available capacity.
- Continuously measure and improve. Measure the flow through the system using the basic Kanban flow metrics (Lead Time, Throughput, WIP), and then improve the flow by setting/adjusting WIP limits at each process step, and by defining/adjusting workflow policies.
These 3 practices are interconnected and all are essential to achieve the goal. Leaving one or more of them out means you are unlikely to achieve the overall goal of the Kanban Method.
Kanban Artifacts
Two primary artifacts are essential to support the Kanban Method:
- Kanban Board
- Continuous Flow Diagram (CFD)
These artifacts are designed to maximize the transparency of critical information so that everyone has a common basis for taking action.
Kanban Metrics
Measurement is a fundamental element of the Kanban Method, and 3 key metrics are used in support of Kanban goal of flow optimization:
Lead Time. This measures how much time it takes for a work item (for example a task or user story) to go through a process from end to end.
Throughput. Throughput is a measure of how many work items can be delivered per unit of time by the process. For example, cellphones manufactured per month, or user stories delivered per day. It measures the production capacity of a system.
Work In Progress (WIP). A fundamental ingredient of the Kanban Method is limiting work-in-progress.
The relationship between these parameters is described by Little’s Law.
Continuous Improvement
Once a team has a basic Kanban system in place (a Kanban Board with WIP limits and workflow policies), a cadenced process for measurement and improvement must be instituted. The analysis of flow through any Kanban system is done most effectively using a Cumulative Flow Diagram. The CFD Diagram is one of the primary artifacts of the Kanban Method, and is used to measure flow performance, identify bottlenecks in the process, and to help identify opportunities for improvement. The CFD shows the distribution of work in each of the workflow states and how that distribution trends over time. Each band in the diagram shows the number of work items in each state of the workflow.
Putting it all Together
Fundamentals:
3 Fundamental Practices:
- Visualize the workflow
- Apply WIP limits at each step of the workflow
- Measure and Improve the Workflow
- Measure and adjust WIP Limits
- Define/Adjust workflow policies for each step of the workflow
- Balance/re-balance capacity applied to each workflow state (no step overloaded, no step idle or waiting for an upstream step).
Important points:
Important Points:
- Standardizing processes via workflow policies
- Bring transparency to the work – make the process amenable to inspection and adaptation
- Make processes repeatable and the flow rate more predictable
- Planning accuracy (for those that plan)
- Reduce variability of the work itself
- For software development this means small stories.
- Small stories (or work items) improves flow through the system
If we were to summarize how the 3 practices, 2 artifacts and 3 metrics combine to support Kanban objectives it might be as follows:
Scaling Kanban Across the Enterprise
We’ve just been discussing application of the Kanban Method by development teams. Kanban can be applied at all levels of the enterprise. Work is done at different levels of abstraction, but the fundamentals involving visualization, WIP limits and measurement are exactly the same.
Across an enterprise, workflows will be designed to address different levels of concern, and hence the layout of Kanban Boards will vary. For example, a portfolio management team might use a board to track strategic initiatives (or Epics in SAFe). A program management team might design a board to track the intake and refinement of program features in preparation for program planning (or PI Planning).
Three types of Kanban Boards and typical workflows are in use:
- Portfolio Kanban: For managing a portfolio of programs (or epics) across a larger organization. Typical Workflow: Idea Funnel, Analysis, Backlog, In Development.
- Program Kanban: For preparing and managing the backlog for a single program that will be delivered by several teams. Typical Workflow: Intake Funnel, Analysis, Ranking, Program Backlog.
- Team Kanban: Team tracking of User Story delivery. Typical Workflow: Backlog, In Development, In QA, PO Review, Done