Burndown Charts answers your question, "Can all tasks be completed by the due date?" at a glance. Burndown Charts plot "hours remaining" vertically and "schedule to complete the milestone" horizontally, and shows the tasks left to do over time. The whole chart shows the milestone.
As time passes, the outstanding tasks decreases. The lines in the graph will have decreasing slopes when viewed from left to right.
There are 3 lines in the Burndown Chart.
This line shows the actual result of the progress and the currently outstanding tasks. The "estimated hours" will decrease as tasks are completed.
This line shows the estimated progress. It is calculated from the "Due Date" and "Estimated Hours". The Actual Line overlaps the Estimated Line when tasks are completed as planned.
This line is drawn by averaging the amount of tasks over the number of days. This line can be used to verify whether the plan is appropriate.