With the recent spread of Agile project management, companies have become focused on streamlining their operational processes. From product vision to product delivery, everybody wants to minimize delays and get out on the market as quickly as possible. The Kanban Board, an artifact of the Kanban methodology, is a useful tool to enhance work processes across sociotechnical systems.
Roots of Kanban Methodology
The roots of continuous delivery lay in 1940’s Toyota assembly lines. The workflow there was focused on the ideal of “just in time” production, where inventory is minimized and materials don’t sit around waiting for the next processing step. It is a “pull” based system, which separates a workflow into stages. The throughput must be managed so that material moves smoothly through the stages and doesn’t result in any build-up or waiting. There are no uncompleted tasks, backlogs, or pauses in production. Inventory and work-in-progress have a quantifiable cost to the organization, so the optimization of just-in-time manufacturing systems results in strong financial performance.
The Kanban Board
The Kanban Board is constructed of physical tokens and a board which has columns representing the stages of production. This board was used to manage the “just in time” production system previously described. The Kanban Boards used today do not substantially differ from those of the Toyota production system. Many teams still use a physical board, with cards of different colors representing different tasks. The “stages of production” are adapted to the type of company (for example stages in a software development release pipeline). Other teams choose to use digital boards within their organization. Example workflow stages for a software development team might be:
- To Do
- In Progress
- Ready for Deployment
- Quality Assurance
The number of tasks in each column should be constrained, in order to support a smooth flow of tickets through the workflow - just like the material through the factory in a just-in-time production system. Accumulation of a large number of tasks in one column signals a bottleneck that needs to be addressed by the team. While work-in-progress and inventory in software development may not have as tangible a cost as in manufacturing, these should still be minimized. The value for work done is not realized until it is released to the customer, so the ticket should move to production deployment as quickly as possible. Additionally, a small amount of work in progress helps the team focus and minimize context shifts.
Kanban boards have a long history and a bright future. It’s worth understanding the basics of this tool.