Read a burn-down chart (一张燃尽图)

Sprint Burndown Chart is a unique artifact, which indicates total remaining Product Backlog Item (PBI) towards the end of sprint.

It tells the Dev team and Scrum Master,

  • Where they are in the schedule, at the right moment (by day)
  • If their original plan is estimated over-granular

It tells the product owner (PO),

  • if the original sprint plan is still optimistic, or if any adjustment should be considered

Take this burn-down chart for example (weekend deducted)
  • This sprint last two and half weeks, 13 working days
  • Planned work is 50 story points
  • Sprint scope goes up on 24th Jul
  • No stories completed over two days since 27th Jul
  • 60% of work was completed in last 3 days (23% of sprint length)

Maybe you read more out of this chart. But I doubt it

In another hand, take a look the raw data that builds up the burn-down chart above

  • Scope change on day 5, day 8 and day 12
    • these are not necessarily obvious on burn-down chart. But it could be a topic to discuss about on retrospective meeting
  • User story 187 was closed on day 3, and reopened on day 5
    • It caused the scope “vomit” on burn-down chart
  • Many lower prioritized stories are completed (on day 6), ahead of higher prioritized stories (user stories are prioritized in sequential order)
    • Is this how PO wants?
    • Is it because top stories are more sized (complicated), so Dev team intentionally chose lower stories to do?
  •  After 8 working days since sprint kick-off, high priority user stories 151 and 189 are are still open
    • They are both 5 story points (relevantly complicated). Could it be the stories are too complicated for team to accomplish?
    • Is this how PO wants?
    • Is there any dependence blocks the progress?
    • Was the team over-optimistic in estimation?
  •  User story 173 (5 point) was removed and replaced by user story 160 (5 point) after one week since sprint start
    • It doesn’t mean we have the whole sprint to accomplish user story 160, as we planned for 173
    • All effort spent on 173 (if any) was wasted
  • 7 user stories (8.5 points) were completed on day 6 (26th); 12 user stories (32 points) were completed on day 11 & 12
    • could they have been resolved and pending for review since earlier? if so, could we bring validation ahead?

You probably could generate more questions than I do. This is why I suggest to keep track of raw data than just few dots on burn-down. It’s always interesting to look into hidden facts within the raw data 🙂

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