Hi I am using Project 2016 and met a client yesterday and found a difference in the way Project calculates Total slack. My client has the latest update and I do not.

The difference is when I use Manually Scheduled Summary tasks. In my version Project checks the Finish date of the Manually Scheduled Summary task as a time set task so if the subtasks has a total duration of 8 Days and the Summary task a duration of ten Days the total slack is 2 Days.

In my clients version the finish date of the Manually Scheduled Summary does not effect the total slack calculation at all. But the way I see it, this new calcualtion is wrong. Because if I have a deliverable and the Summary task is set to this date I want my total slack to use this date so I can use the critical tasks correct.

I dont like this change but I dont Think I can persuade Microsoft to change it. So what do you Think is the best way to adapt to this new change?

Hugo