Many teams I’ve seen using Kanban do a good job of visualising blocked work. A common practice is to throw the blocker sticker away once the work has been unblocked. I always get teams to keep the blockers so they can review them for patterns or common sources of blockage at retrospectives. Even in the first 3 months of Kanban teams have taken action to address regular occurrences of blockage from a single source. For this practice to be effective its important for teams to capture the right information on the blocker sticker, i.e. cause of blockage, date blocked, date unblocked, and any other information to help at a future date when reviewing.
As a coach I’m constantly looking for what I call “board smells” during stand-ups. One particular board smell is that of reviewing blockers rather than attacking them. Some teams become complacent and seem to skip over blockers after a while so a regular reminder and prod is required to get them to unblock work either through escalation or better still, get the blockee to attend the stand-up.
In the IT Ops arena, 3rd party supplier interactions are common. This results in frequent blockages due to waiting on 3rd parties aka external blockages. I’ve found that internal blockages are far easier to resolve than external blockages. Teams have found that when dealing with 3rd parties they don’t have enough contractual leverage to resolve blockages quickly enough. These blockages are moved to a separate area of the board so they are highly visible. Its then down to senior management to apply maximum pressure on suppliers to unblock.