Removing shipped items from cumulative flow diagrams

Question

I've just implemented kanban on my team and have started tracking the states of items across time. We've come to the point we we're about to ship our first release under this system, and I've got a question about what to do with finished work items.

We have a state "completed" that represents a work item that has been customer accepted and is ready to ship. The idea is to remove items completely from the board as they are shipped, or as they are considered to be "done done" (for things like infrastructure tasks, etc.). However, if we remove items from complete, the CFD takes a big dip down (for instance, we have 11 completed items right now, compared to 14 items in "active" states, e.g. not backlog). I'm okay with doing this, as it quite clearly shows when releases happen, but I haven't seen any published CFDs that do this. Every CFD that I've seen seems to trend upwards forever.

Is there any sort of consensus or "best practice" (with all the caveats that that term implies) that speaks for or against removing items from the CFD? It's worth noting that I am tracking shipped / closed items, for purposes of engineering and end-to-end cycle time, but those metrics are being tracked separately.

Answer 1

Wow, not a lot of Kanban action around here :)

After some discussion on this topic on the kanbandev mailing list, I've decided to go ahead and track these. I've changed my previous "Completed" stage to be "Ready to Ship" (still contained on my board), and created a new state called "Shipped / Closed". Shipped / Closed isn't on the board, but I keep track of it in a separate spreadsheet (where I'm keeping track of other things like lead time, etc.).

Answer 2

What you could do is use a release ID as a separate field for filtering already-shipped items out of your CFD. If you're really running kanban, then you have WIP continually, at different stages of the workflow, and so you don't want to lose the status of current items. You should see the entire chart 'shift down' at a release as the released items drop off the chart, but this should also give you some continuity on in-progress items.

You might also want to save a snapshot of the CFD before the release drops out of scope, in order to look at the deltas between state changes for items through the workflow, so you can see how the deltas compare for the current release. Increased deltas, shown by greater horizontal distances between the various workflow stages in the CFD at a given time, indicate a workflow constraint that you should look at; teams can't get better forever, but they shouldn't be getting worse.