The schedule for WBS elements refers to the start date,
finish date, duration, and effort information. The schedule calculation
includes the working days and hours that are specified in the project
calendar. In a WBS structure, the schedule for a parent element is
determined by the schedules of its child elements.
To create a schedule, specify the expected start date,
end date, and duration. If you enter any two of these fields, the
third field is calculated and displayed. For example, if you enter
the start date and duration, the finish date is calculated and displayed.
This calculation includes the working and non-working days in the
project calendar.
For example, if the project calendar has
Saturday and Sunday as weekly holidays, and you specify the start
date for a task as January 1 (Monday), and the duration as 10 days,
the finish date is calculated as January 12. If you enter the start
date as January 1 (Monday), and the finish date as January 8 (Monday),
then the duration is calculated as 6 days (Saturday and Sunday are
not counted as working days).
Note: Programs do not have calendars,
and the schedule calculation for programs does not include calendar
exceptions. The start date of a program with child projects is the
start date of the earliest project. The finish date of a program with
child projects is the finish date of the latest project.
Effort is
a non-editable field that is calculated and displayed based on the
duration of the element and the work hours per day that are specified
in the project calendar. For example, if the project calendar specifies
8 hours of work per day, then for a task duration of 10 days, the
effort is calculated as 10*8 = 80 hours.
The expected effort
for programs, projects, iterations, and summary tasks is zero when
they do not contain any child elements. After child elements are added
to these elements, the expected effort is rolled up from the effort
of the child work items.
To modify the schedule of a parent
element, you must modify the schedules of its child elements. Any
change that you make to the schedule of a child element is rolled
up to the parent element, and the parent element schedule is modified
to reflect those changes.
Default schedule
When you create a new element
(project or WBS), a default expected schedule is created for it.
- If the new element is a root element, such as a new program that
has no child elements, the default schedule is based on the system
dates. The start date is the current date, and the duration is one
day. The finish date is the same as the start date. If the current
date is a holiday in the project calendar, when you save the element,
the start date is set as the next working date. The effort is the
working hours per day that are specified in the project calendar.
- If the new element is a child element of an existing element,
the default schedule is based on the parent element.
- If the start date of the parent element is the current date or
later, the default start date of the child element is inherited from
the parent. The start date of the child element is the start date
of the parent element, and the duration is one day.
- If the start date of the parent element is earlier than the current
date, the default start date for the child element is the current
date, and the duration is one day. The finish date is the same as
the start date. If the current date is a holiday, when you save the
element, the next working date is set as the start date.
By default, the planned schedule is the same as the expected
schedule until resource or profile assignments are created for the
work items.
Modification of the default schedule
To
create a schedule, you need to modify the default schedule and enter
your own start and finish dates and duration for the elements.
When
you modify a schedule field, the dependent field is recalculated as
follows:
- If you modify the start date to an earlier start date, the duration
is increased. If you modify the start date to a later start date,
the duration is decreased. The finish date is not affected by either
of these changes.
- If you modify the finish date to an earlier finish date, the duration
is decreased. If you modify the finish date to a later finish date,
the duration is increased. The start date is not affected by either
of these changes.
- If you increase the duration, the finish date is postponed to
a later date to accommodate the new duration. If you decrease the
duration, the finish date is brought forward to an earlier date to
match the new duration.
Rolled-up schedule information
When you
add a child element to an existing element, the parent element schedule
fields are disabled, and you cannot directly modify them. The parent
schedule is rolled up from the schedule of the child elements.
Note: The
expected schedule of an iteration is entered manually, and it is not
rolled up from the work items assigned to the iteration. Only the
expected effort is rolled up from the assigned work items.
Schedule
fields are rolled up as follows:
- The start date of the parent is the start date of the earliest
scheduled child element. The actual start date is rolled up to a parent
element as soon as any of the child elements is started.
- The finish date of the parent is the finish date of the latest
scheduled child element. The actual finish date is rolled up to a
parent element only when all the child elements are complete.
- The duration of the parent is the available working days, as specified
in the project calendar, between the start and finish dates that are
rolled up from the child elements.
- The effort of the parent is the sum of the effort of the child
elements.
Calculation of a project schedule
Based
on the roll-up rules, the expected schedule for a project is calculated
as follows:
- The start date of the project is the start date of the earliest
scheduled project element, including iterations, if any.
- The finish date of the project is the end date of the latest scheduled
project element, including iterations, if any.
- The duration is rolled up from the duration of the project elements.
- The effort is a sum of the effort of all of the project elements.