Sprint Burndown Chart : hours left, but not burnt ones

this is a burndown chart I found from our office. On this chart, everyday the numbers used are minused / burnt hours, instead of remaining hours. My first impression was surprising, quickly took a photo and planned to record it down as a negative sample.
Right before start writing, I felt it’s so bad without confirming with the team, then I came. And the answer is :
– they use task board, with "To Do", "On-Going", "Done"
– every task has an estimation in hours
– no update on task estimation at daily scrums
– directly move the task from "On-Going" to "Done" if task is finished
– the total hours of finished tasks is the minus number updated on burndown chart
So here it means, the 1st day, team completed tasks with 22 hours original estimation; the 2nd day, 52 hours; the 3rd day, 39 hours; etc. Well, it’s 22 hours, no matter how many hours are spent actually, nor updating those left tasks.
There is one practice with Burn-Up Chart, which starts from 0, everyday the burnt user story points or values are updated to that chart, then it represents the potential value realizing everyday.
Risks using similar practice with houred tasks are :
– perhaps no learning happen to improve estimation later
– no updates on left tasks, so latest status is not clear, nor how much time still needed to DONE
– bigger original estimation for the sake of fake satisfaction from many burnt hours
– etc.
All in all, it reduces the opportunity for team to "Inspect and Adapt".

Xu Yi is a professional Agile & Lean Coach, check out more at http://kaverjody.com/about/.