Another major cause for long lead times are blockers. Blockers are things that prevent the flow of value / work from being done. Often these blockers are caused by things outside the system that we often have little or no control over. As these are a major cause of “tail lead time” issues, you should identify blockers and come up with countermeasures to prevent the key problems from affected your customer delivery.
Some examples of blockers include:
- Waiting for a particular specialist to perform work
- Waiting on another team / group to provide a something such as:
- Waiting on procurement for setting up agreements
- Waiting for security / compliance to provide a review
- Waiting on legal for advice
- Defects / quality issues (although often we separate these out as a specific kind of blocker)
Often times, I see boards that take blockers and place them in a separate column or waiting area. For example:
You should avoid this kind of mechanism for a number of reasons:
- These areas are out of sight / out of mind. They often get forgotten and don’t get solved in a timely manner
- They are (usually) not WiP limited – this will cause unpredictability in your system of work
- They don’t become the focus for improvement
- When they become unblocked, often you forget where in the flow they were up to before they became blocked and it becomes hard to place them back on the board
You should try, instead, to block the ticket in place and record it with a blocker stickie such as the example below:
The blocker stickie should also contain enough information that you can use it for analysis at a later date to combat commonly occurring blockages that are having the largest effect on your lead time or other fitness criteria (I’ll cover blocker clustering in another post). Here’s an example blocker stickie:
Key things to capture:
- The work item that was blocked
- A blocker description (what is blocking the ticket)
- The date the item became blocked
- The date the item became unblocked
Along with this, you should also work with your leadership team to let them know what these mean. Leadership should be on the lookout for blocker stickies and actively engage the team asking questions like “how can I helpâ€, “what can I do to remove this blockerâ€. Keeping your blocked item in the flow will ensure that eventually your WiP limit will be reached which will force you to deal with the blocker.
Blockers are a commonly occurring event in Kanban systems (particularly new ones) and they should be identified in the right way with the right data. The Kanban system should be set up with feedback loops and policies that force you to deal with the problems that cause blockages to ensure that you maintain a healthy flow. If you don’t deal with blockers in this kind of way, your system of work will continue to be unpredictable and experience much longer lead times than it should.