Summary Task Duration not Whole Days?

[Sara Miller]

I have a Summary Task call "Inputs" with multiple subtasks all of which are
milestones (duration = zero days). Each of these has an external predecessor
link to multiple subprojects. The tasks to which they are linked are also
milestones. In all cases the resource field is not used.

Why does the duration in the Inputs Summary task have a fraction of a day
(648.25 days)? All of the subtasks are zero day milestones.

 

[Steve House]

The summary task duration extends from the start date and time of the first
milestone to the end date and time of the last milestone. That's implicit
in the definition of "duration." Durations are not additive in a summary
task regardless of whether the subtasks are performance tasks or milestones.
Durations are always computed in minutes. If the earliest and latest
milestones don't happen to occur at exactly the start or end of a workday,
the number of working minutes between them will calculate out to some
decimal fraction when divided by the hours in a day in order to convert them
to workdays for display on your task table.

FYI, a task list that consists of nothing but milestones is useless for
scheduling work or monitoring progress and budget. From what you describe
as to what you have right now, you don't have project plans at all - you
have to-do lists outlining the goals you hope to achieve but there's nothing
there to actually help you organize and direct the work so you can manage to
achieve them. You're still flying as blind as you'd be if you weren't using
Project at all.

 

[Sara Miller]

Thanks for the explanation Steve — and a clarification: I was describing the
behavior of only a section of the schedule. Yes, I do understand the role of
milestones and tasks...

The summary task duration extends from the start date and time of the first
milestone to the end date and time of the last milestone. That's implicit
in the definition of "duration." Durations are not additive in a summary
task regardless of whether the subtasks are performance tasks or milestones.
Durations are always computed in minutes. If the earliest and latest
milestones don't happen to occur at exactly the start or end of a workday,
the number of working minutes between them will calculate out to some
decimal fraction when divided by the hours in a day in order to convert them
to workdays for display on your task table.

FYI, a task list that consists of nothing but milestones is useless for
scheduling work or monitoring progress and budget. From what you describe
as to what you have right now, you don't have project plans at all - you
have to-do lists outlining the goals you hope to achieve but there's nothing
there to actually help you organize and direct the work so you can manage to
achieve them. You're still flying as blind as you'd be if you weren't using
Project at all.
--
Steve House [Project MVP]
MS Project Trainer & Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs

I have a Summary Task call "Inputs" with multiple subtasks all of which are
milestones (duration = zero days). Each of these has an external
predecessor
link to multiple subprojects. The tasks to which they are linked are also
milestones. In all cases the resource field is not used.

Why does the duration in the Inputs Summary task have a fraction of a day
(648.25 days)? All of the subtasks are zero day milestones.

 

[jim_c500]

I too have this problem. Three subtasks of 20 days, 20 days and 30
days, spanning a total of 35 days (they partly run cuncerrently) give a
summary task duration of 35.14 days. There are no predecessors,
milestones or task links, just three separate tasks under one summary
task.

Everywhere else in the project summary durations show as full days,
it's just this one which shows as a fraction. Calendar looks okay,
tasks are full days, not part days, there are no dependencies skewing
the dates.

An idea why I'm getting the .14 of a day?

Thanks, Jim

 

[John]

I too have this problem. Three subtasks of 20 days, 20 days and 30
days, spanning a total of 35 days (they partly run cuncerrently) give a
summary task duration of 35.14 days. There are no predecessors,
milestones or task links, just three separate tasks under one summary
task.

Everywhere else in the project summary durations show as full days,
it's just this one which shows as a fraction. Calendar looks okay,
tasks are full days, not part days, there are no dependencies skewing
the dates.

An idea why I'm getting the .14 of a day?

Thanks, Jim

Jim,
You mentioned that the calendar looks okay but it sounds like there is a
resource calendar on one or more of the subtasks of that summary that
are not consistent with the task or project calendar. So, check the
working time calendars of all resources assigned to those tasks.

John
Project MVP

 

[Jan De Messemaeker]

Hi,

Show time of day with start and finish fields (Tools, Options, View, Date
Format) and you'll find a 1 hour shift somewhere
HTH