In A kanban workflow for product development, I mentioned that one of the benefits of kanban is that the board communicates information visually. The location and movement of cards on the board can indicate numerous project risks, which can be any of the seven wastes of lean. Learning to read these patterns can help you identify and address issues before they become problems.

Near empty backlog

The product manager or project lead is typically responsible for ensuring the Backlog is populated. Cards in Ideas are promoted to the Backlog when their requirements are complete and stakeholders have agreed that a given card is an immediate priority.

When the Backlog is almost empty, the product manager or project lead needs to allocate time to add more cards to the Backlog.

If the Backlog becomes empty, individual contributors have no tasks to work on. That means these people are WAITING for things to work on, which obviously wastes money.

Too many cards in the Backlog

A more common issue is that there are too many cards in the Backlog. Ideally, all cards in the Backlog have the same high priority. In theory, any card that an IC works on is appropriate. But if the Backlog has too many cards, it’s likely that some of those cards are no longer a high priority.

If someone works on a card that is not a priority, the whole thing could be considered MOTION waste. Ultimately, it is a prioritization DEFECT.

Following just-in-time principles, cards shouldn’t get too much detail until they are near ready to work on. Too many cards in the Backlog is a form of OVERPRODUCTION, which leads to too much INVENTORY. This inventory of requirements will either change or become obsolete, which is wasted effort.

Too many cards In Progress

Cards In Progress mean they are actively being worked on. Each day they are In Progress, there should be a progress update as a comment in the card.

In general, each individual contributor should work on at most two cards simultaneously. If an IC works on more than two things, she runs the risk of MOTION waste due to task switching. It can also lead to increased DEFECTS.

Too many cards In Progress is therefore a sign of MOTION waste due to multitasking. It’s often useful to see whether any single person has too many cards. Isolated cases can be corrected easily by the project manager, whereas a more general discussion is required if most people are multitasking.

Stale card In Progress

In our Kanban approach, every card should be completed in at most two days. This rule ensures that work is subdivided into independent cards as much as possible, which promotes fungibility.

Cards stuck In Progress can indicate a few problems:

• there’s a DEFECT in requirements resulting in time wasted during implementation,
• the individual contributor is OVER-PROCESSING and doing too much work,
• the card was deprioritized or forgotten, meaning people aren’t adhering to the kanban rules

Too many Blocked cards

Cards that are Blocked cannot be worked on because some other card must be completed first. This indicates a task dependency due to a requirements DEFECT. In theory, the dependency should have been identified when the card requirements were drafted, but these oversights are bound to happen.

That said, with a robust design process, it should be rare for cards to appear in Blocked. If too many cards are Blocked, it means one of two things: either

• the product manager is not meeting expectations and producing too many requirements DEFECTS, or
• individual contributors are introducing process DEFECTS and not using the Blocked column correctly.

For the latter situation, people can get confused about the meaning of the Blocked column. When an IC needs to switch to a different task, such as to fix a bug or help with a higher priority issue, it’s common that she moves the card to Blocked, even though this is incorrect. The card should really be moved into the Backlog, since in theory someone else with spare capacity can pick up the task.

Card stuck in For Review

Cards move through a kanban board like an assembly line. The goal is to maximize throughput (or flow rate) by moving as many cards through the process as possible. Cards that move from In Progress to For Review are nearly done. However, this stage is often a bottleneck in the process. Who is responsible for moving cards out of For Review? The card owner is, but they rely on someone else to review their work. This coordination point can stall progress, particularly if reviewers are also individual contributors.

Too many cards For Review indicates a process breakdown. The cause is usually due to uncommunicated or misunderstood expectations. Aside from the card owner being responsible for coordinating and pushing for a review, all reviewers need to allocate sufficient time for reviews. If this isn’t happening, then incentives may need to be adjusted to align with maximizing the flow rate.

Card cycles from For Review to In Progress

Ideally, only a single review is required for a card. Unfortunately, some cards may cycle between In Progress and For Review. Cards should never be trapped in this cycle as it is a sign of OVER-PROCESSING or DEFECTS.

Numerous issues can surface when a card is stuck in this cycle:

• DEFECT in requirements - insufficient requirements often results in an incorrect implementation
• DEFECT in execution - poor quality code warrants additional work to improve quality
• OVER-PROCESSING in review process - too much nitpicking can lead to more work than necessary

Conclusion

In a healthy kanban process, cards move regularly through the board, in one direction. Boards with stuck cards or overflowing columns are like backed up toilets that must be cleared out or risk an even bigger problem. Use these visual cues to root out blockages and prevent serious problems from forming.

What insights can you gain from reading a kanban?