This is a demonstration of how to read an earned value graph. The black line represents the planned cumulative budget expenditures, the green line represents the actual expenditures, and the blue line represents the earned value. The project is ahead of schedule when the earned value line is above the planned budget line, and is under budget when the earned value line is above the actual budget line.
Move the mouse over the graph to see the relevant comparisons. Horizontal brackets indicate a schedule variance, while vertical ones indicate a budget variance.
You should note that at the end of week 1, the project is 4 days over budget, even though the expected amount of budget has been spent. This is because only 6 days worth of product was actually built. This makes the project .4 weeks (2 days, assuming 5 days per week) behind schedule (4 labor-days of work not completed / 2 labor-days per calendar day). Graphically, this is obvious because the blue earned-value line is below both the planned and actual lines.
At the end of week 2, the earned-value and actual expenditures lines are equal, indicating that the project is now on budget, and has improved to only one day (.2 weeks) behind schedule. Week 3 shows the project still on budget, but it has now slipped back to .4 weeks behind schedule.
After 4 weeks, the productivity (indicated by the slope of the earned-value line) has picked up, and the project is now on schedule and 4 labor-days under budget. This can be seen from the fact that the blue and black lines intersect, and both are above the green expenditures line. At the end of week 5, the blue line is above both of the others, indicating that the project is now both ahead of schedule and under budget.