How Cumulative Flow Diagrams(CFD) can help Scrum Teams
CFD's are diagrams showing the work load of each stage in a value stream and the trend of the work load. In product development when you use Scrum, each work item in the team's backlog moves across its value stream,
e.g ready -> planned -> development -> test ->UAT->DONE -> Deployed.
A CFD shows (typically daily) how many work items there are in each activity.
CFDs are common in Kanban and I am finding them also very valuable for some Scrum Teams.
At first I thought it would be meaningless since I though I wouldn't get much use of the diagram for a 2 week Sprint. When things are already visible on a Kanban board (I find Kanban boards more transparent than a Todo-in prog-done board) , what can the CFD serve? Once I start experimenting it with some teams, I realised the diagram helps teams that are not able to complete their PBIs that they forecast for the Sprint. Lots of teams overcommit for many reasons(lack of safety in most cases) and CFDs enhances the transparency to show where things usually pile up in the flow. Besides you don't have to do a Sprint only CFD, you can just continue so you can compare how the diagram evolves in the subsequent Sprints.
When teams look at a CFD and take some actions to create a better flow, they can easily see the affect of these actions on the CFD. Below is an example from a team I've been coaching. This team had first realised they had a problem at their UAT(not in the diagram) where things were piling up. Once they sort of addressed this problem now they realised they have too many items in development and test as seen. Therefore the "DONE" trend is very low. Now next action can be to limit the number of "in progress" items as an experiment to increase the output. Hope the team can achieve this given they feel safe not to over commit.
Most teams struggle to limit their WIP which is a Kanban practise as well as a Scrum value (focus). Scrum is a great framework to address complex problems collaboratively in an iterative incremental way. One of the core values focus in unfortunately not always respected or well understood. Scrum emphasises finishing a DONE increment at the end of each Sprint however it leaves the "how" part to the teams which is fair. Using WIP limits helps the team to create focus, using a CFD can show how much there is focus in the team. Transparency enables inspection and adaptation.
I reckon CFDs can be an alternative to Sprint burn downs for some teams. Give it a try if it made sense.