Summary duration does not equal total of sub tasks

[Sally]

I created four tasks and demoted three to create a summary task. The summary
task duration is not the total of the summed duration of the demoted tasks.
However, the % complete is calculated using the correct total of the three
demoted tasks. What am I doing wrong here???

Thanks

 

[Dale Howard [MVP]]

Sally --

The summary task does not total the Durations of each subtask. Instead, it
calculates the Duration from the Start date of the earliest task to the
Finish date of the latest task. Please note that a summary task DOES total
the Work and Cost values for each subtask, but it never totals the Duration
values. Hope this helps.