go to task usage view, and then move your mouse over the right side where you see all the number and dates like excel table. and when your mouse in that right side, right click your mouse and you will see a menu. simply check cumulative cost. and that cumulative cost will be added as one of the rows to that right side. that is your cumulative costs over time. that is going to be your s-curve data. so now all u need to do is to copy and paste two rows to the excel… dates and cumulative cost. this will make your s-curve… in excel, in one row, paste all the dates. and then paste all the cumulative cost in a second row, exactly under all corresponding dates. then all you need to do is to plot a graph in excel, which will use those two rows, which are dates vs cumulative cost