One common question that often pops up when teams are starting with Kanban is, what is the correct limit I should set for each of my workflow statuses? The answer is simple: try and experiment.

The first step is to look at your board and see if any constraints are being violated. If we take a look at the following example of a Kanban board, we can see that too many issues are in the In Progress column, and at the same time, we don't have enough issues in the QA column. What this tells us is that we have a bottleneck in our development phase of the workflow. This results in work being piled up in development while the QA engineers are waiting around and not being productive:

So in order to address this, as a team you will need to take a close look at the bottleneck—in this case, the In Progress column—and figure out why this is happening. For example, perhaps you do not have enough developers to handle the workload and people are multitasking in order to try to complete as much work as possible. This will often cause unnecessary context switching, which in turn causes inefficiency, or perhaps the tasks are too complicated and need to be broken down.

Defining the column constraint can be an art, and once you have set the constraints, you will need to periodically review them and refine them as the project and team changes. When setting column constraints, keep the following points in mind about the limits you choose:

• Limit set too high: You will have idle tasks sitting around, and this will lead to bad lead/cycle time.
• Limit set too low: You will have idle people waiting for work, and this will lead to bad productivity.

Remember, with Kanban, you and your team should continuously improve your process; the board helps you to highlight any potential bottlenecks, so you and your team can improve your processes.