But two problems can arise:
1. Teams get used to collecting data, but forget to interpret and take action on it.
2. Executives may look at the graph and become concerned if the actual numbers don't track precisely to the projected line.
So how do you know when to be concerned versus when the numbers are varying normally? An average of 20 percent variance is a good rule of thumb. Anything less is a false alarm. Anything more demands attention.
Here are some models I've created of possible scenarios, but in reality, progress is more of a wandering curve. The vertical axis shows how many hours are left and the horizontal axis shows how many days are left. The straight blue line represents the planned amount of work left each day in hours, while the red line shows the actual hours left.
Case 1: Under the line
The team consistently finished more work than expected. Does this represent an error in estimation or natural variance in the system?

The team is running behind, but is close enough that it will still complete the work for the iteration.

Case 3: Above the line -- in trouble
The team is so far behind, it must stop and take action to address the problems or re-plan the work. This progress line is a powerful warning signal.

How do you use burn-down charts?


As long as your sprint is completed at the end, you shouldn't take too much stock in whether or not you spend the majority of said sprint on one side of the line.
You should only be concerned if this activity forces a change in work at the end of the sprint. Clearly if your team is slowing down so they do not have to pull more backlog in, then you have a problem. Even worse, if your team is putting in more hours at the end of sprints to complete this work, then you will soon have a burnt out team.
With either of these two problems you have yourself a team with a velocity problem that needs to be addressed.
First I would like to congratulate you for the article.
Now, so we can have a good monitoring of the project, you need to plan. Plan is for me to say who will do what when and how long it takes.
Without this information I see using the burn-down is a team trying to keep the route of a boat without knowing the effort and struggling to reach its goal.
In the leadership book "Gung Ho," there is a discussion about using visual aids to set goals and when you reach the goal you celebrate.
In your communities you often see visual aides like thermometers used in fund raising. You have schedules for your project's overall progress. Burn-down curves represent the visual short-term goals that you should post to show short-term progress. When your team reaches their goal, you reward them with a celebration (small or grand, the choice is yours).
The progress stays high because people like to feel that they accomplished something. They feel appreciated by celebrating their success. Their success is your success. With that mentality, you shouldn't have to worry about under performing with your management. I think this may provide you with different view of the use of the tool.