Why do we have the Sprint Burndown chart?
As with almost everything in Scrum, the purpose of the Sprint Burndown chart is to help the Team.
First, we assume the Team (the whole team, including the implementers, the PO and the SM) are adults. And, as adults, they want to be successful. In every dimension that is relevant: more fun, higher quality, more customer satisfaction, more business value, reasonable risk — whatever is appropriate in your situation.
To be successful, the Team is responsible for self-organizing, for self-managing, and for self-directing themselves to greater success.
Oh, and I guess we must say that ‘more success’ needs to be achieved in a time-box. And that time-box is likely 40 hours per week (or less). (No one is foolish enough to propose that innovation teams regularly work long hours, right?)
So, the Sprint Burndown chart is where the whole team can ‘see where we are’.
We have the ‘landing a plane’ metaphor because Jeff Sutherland was a pilot.
So, the Team wants to land the plane more successfully each sprint. And recognize the truth that ‘weather’ or other issues happen almost every sprint.
So, the Burndown helps the Team adapt to the situation more effectively.
Hence, the truth is needed, and everyone wants to tell the truth, because they know that the Team can only manage itself to success with more truth. More accurate information.
What does it mean to self-manage? We do not define that much. Anyone in the Team can help manage the team. Can say ‘yikes, we’re screwed!’, or ‘I think our biggest impediment is X’, or ‘I think the way to fix Y impediment is Z’, or ‘Ok, I’ll help work on that impediment now!’.
We look for emergent leadership. Leadership can be inspiring or practical. Helpful. It might be Servant Leadership style or maybe not quite. (I am not recommending command and control style leadership.) But, in any case, it helps the Team succeed.
Hope that clarifies the purpose of the Sprint Burndown and who uses it.
We have many dysfunctions with Sprint Burndowns. We hope that, if they understand why we have a Sprint Burndown, it starts to get easier to fix all the possible dysfunctions.