Wednesday, February 10, 2010

Sprint Burndown says a lot about your scrum team...

A Burndown chart is the graphical representation of amount of work left to do (y-axis) versus time (x-axis) and can help get a good heart-beat on how a scrum team is performing.

Some questions that Burndown can help us answer are:
  1. How good is this team with the planning?
  2. How well is this team executing against the planned stories in a Sprint?
  3. Is this team self-organized and are they working in unison as a "team"?
  4. What improvements can this team make?
Let us take few Burndown examples and try to answer the above questions.



Ex. 1: Line 1 – the Blue Line:

What does Line 1, the Blue line, tell us?
1.       How good is this team with the planning?  Not too good. This team's Burndown never reached zero. This might mean many things –
·         They might have planned for more stories then they could deliver in a Sprint.
·         They might have discovered unknowns after the planning meeting which translated in creation of new stories/tasks.
·         Sprint priorities changed after planning and that resulted in churn of stories.
·         The code quality of feature delivered might have been poor and that translated into defects, increased technical debt and eventually additional tasks/stories in the current Sprint.

2.       How well is this team executing against the planned stories in a Sprint?
·         Honestly, not too well. Their Sprint Burndown is all over the graph.

3.       Is this team self-organized and are they working in unison as a "team"?
·         It might be premature to deduce anything directly from this line. However, if this team has been in existence for a while, it would help to see their past Sprint Burndown and validate if similar trend occurred in the past.  If yes, this might be an indication that the team needs some extra coaching.

4.       What improvements can this team make?
·         Sprint Planning: This team definitely needs to improve in their planning. They should spend more time designing their stories upfront and might also consider breaking their stories into granular tasks.
    
Ex. 2 : Line 2 – the Purple Line

What does Line 2, the Purple line, tell us?  
How good is this team with the planning? 
·         From the first look one might get an impression that the team did well as their Burndown reached zero. But if looked at carefully, the story Burndown rate was way off the ideal Burndown line. Another thing to notice is the steep dive in the Burndown towards the middle. The steep dive can mean one of the following:
1.       The team did not proactively update daily data for the Burndown charts.
2.       Uncompleted stories were moved out of the current Sprint

The answer to rest of the questions is similar to questions from “Line 1”

Ex. 2 : Line 3 – the Green Line

What does Line 3, the Green line, tell us?  
1.       How good is this team with the planning?  
·         Good. They planned enough stories to keep them busy through out the iteration.
2.       How well is this team executing against the planned stories in a Sprint?
·         Good. This team executed to the plan – They inspected and adapted throughout the Sprint. 
3.       Is this team self-organized and are they working in unison as a "team"?
·         Yes, if this is the pattern they have achieved consistently in last few Sprints.
4.       What improvements can this team make?
·         Does not look like this team needs any help as they executed to the plan. However I  think there is always a scope for improvement in planning.

There are many other Burndown patterns that can be analyzed in a similar manner. An additional pattern I can think of for a Sprint is:

If team plans fewer stories than the available capacity, the Burndown will be under the ideal line and go to zero sooner than the end date.