I have been facing this issue at several times that the total number of days in the summary task are incorrect.
For example, in project plan, there are 4 sub-groups. Group 1 has 12 days, group 2 have 18 days, group 3 has 7 days and group 4 has 25 days. The main summary task should have the total of ( 12+18+7+25) = 62 days but it is has 42.
I checked the link of each task and each task is also linked in a sequence.
I could not figure it out that why the total duration is incorrent. I updated my MS Project 2010 with latest patchs / updates.
Anyone who could help me, would be highly appreciated.
If you are using manual mode the totals will not necessarily add up to the total duration. If the tasks are in automatic and are linked FS they should add up to the total duration of each task on the summary. However, customized fields have an option of rolling up and so do baselines.
If one or more tasks has a calendar assigned to it that is different from the Project calendar, you will get resluts such as you describe. For example, using your data I assigned the Standard calendar to the project and a 24-hour calendar to the first two groups. My project duration now is 39 days instead of 62.
Things like this can also happen under certain circumstances if a resource assigned to a task has a calendar other than the Project calendar.
Days in the sumamry line (I don’t like calling them tasks because they are not actually a task) are not additive. It is the working days between the earliest start date of any task in the sub-group and the latest finish date of any task in the sub-group. If for example there are 10 tasks in the group of 10 days each that all start on the same day and all finish on the same day, the total days will be 10, not 100.
Roll up groups above indented groups follow the same logic.