The Kanban board is a primary tool for bringing Kanban’s first core practice to life; that is, it serves to visualise all things helpful for managing work in a Kanban system. This includes:
- Visualising the work through separate objects (e.g. cards, sticky notes) for each work item.
- Visualising the workflow by representing its stages in the columns where the work items flow from left to right. That shall also include clear markings of the crucial points in the workflow, such as commitment and delivery points.
- Core policies within the Kanban system, e.g. the Work-in-Progress (WIP) limits or pull criteria
- Assignments of workers to work, typically through the placement of avatars representing workers.
- Blocked items marked clearly to draw attention to them. In the case of physical boards, this is achieved by covering a work item with a red sticky note.
- Risk associated with the work items.
- Any other information deemed useful for managing the work and its flow by people using the Kanban system. Examples include the visualisation of different work item types or classes of services or tracking measures such as the age of each work item in progress.
The entire Kanban board serves as an information radiator – relevant people can quickly and easily absorb the needed and up-to-date information they need to make the decisions to manage the flow of work.
The usefulness of the Kanban board goes beyond the everyday decisions on what should be pulled to the next column or who should be doing what. The Kanban board may also serve as a trigger for having the right discussions to improve the overall Kanban system. Firstly, it was already mentioned that the board contains information about which work items are blocked – once the item is unblocked, the blocker card might be disposed of. Still, a wiser option might be to collect this information for later processing to discover patterns and common causes for blockers in the Kanban system. Moreover, the Kanban board workflow presents activities that need to be done for the work items and queues. By monitoring the queues, bottlenecks may be discovered and later removed (read more about it in Working with Bottlenecks article). It is worth highlighting here the difference between a blocker (or a block) and an impediment – the latter is commonly used in the Agile community, but its meaning is broader, and it stands for anything that is or may be stopping or slowing down the progress of work in general, whilst a blocker is something that has already stopped the progress of work on a specific work item).