Parameter	Calculation Rule	Notes
Start Date	No start date is specified for a newly created activity. An activity's start date is set equal to the earliest start date of its sub-activities. Sub-activities with no start date specified are not taken into account. If there is no sub-activity with a start date specified, the activity’s start date will be treated as unspecified.	For an activity with one or more sub-activities, ‘Start Date’ is a required field.
End Date	No start date is specified for a newly created activity. An activity's end date is set equal to the latest end date of its sub-activities. Sub-activities with no end date specified are not taken into account. If there is no sub-activity with an end date specified, the parent activity’s end date will be treated as unspecified. However, if a parent activity has had a calculated end date at some stage since it was created, the date will remain in effect even if all sub-activities’ end dates are set as unspecified (their end date field cleared).	Only top level sub-activities, that is, immediately below the parent activity hierarchically, are taken into account in the calculations.
Duration	This value is calculated as the difference between End Date and Start Date	Expressed in days and hours. Minimum non-zero duration is 0.25 hours (15 minutes). Refer to Activity details to learn more.
Progress	Parent activity’s progress is calculated as a weighted mean of its sub-activities’ completion rates, or , where Pi is the completion rate (progress) of the i-th sub-activity, and Di is its estimated hours.	Only top level sub-activities are taken into account in the calculations.
Estimated Hours	These are calculated as a total of estimated hours of all sub-activities the parent activity has.	Only top level sub-activities are taken into account in the calculations.

Changing parent activity’s start date

If a parent activity’s start date is shifted forward or back, the start and end dates of all its sub-ones are recalculated automatically, with their durations remaining unchanged.

Example:

A parent activity had May 03, 2005 as its start date, and had a sub-activity starting on May 10, 2003. Subsequently, the parent activity’s start date was rescheduled to May 1, 2005. As a result the sub-activity’s start date would be recalculated 2 days back, to become May 8, 2006. The sub-activity’s end date, if specified, would move back the same number of days.

Adding a sub-activity with a start date to an activity without

The start date of a sub-activity added to an activity becomes its start date provided it has no specified start date.

Activity dependency effects

If a sub-activity’s start date precedes that of its parent activity as a result of dependency taking effect, the parent activity’s start date is recalculated to be equal to that of the sub-activity.

Public holidays

When a public holiday falls between the start and end dates it is treated as a day off and affects the duration of the activity just like weekends do when 'Treat weekends as workdays' is turned off (see Company Schedule).

Accordingly, if you set a start date and a duration the end date will be calculated taking into account the public holidays and weekends.

Personal schedule & Resource loading

When a personal vacation falls between the start and end date of an activity, it has consequences for your work load. Easy Projects will subtract the off hours according to your personal schedule from your total available hours.

Examples below discuss additional details.

Example:

Case 1. Fred and Mike are assigned to a task that lasts from Monday to Friday (full work week) and it has 80 estimated hours, thus each is assigned half the amount of work. Both have regular personal schedule (eight hours a day, Mon to Fri work week).

With such baseline conditions, the users' work load while working on the task will be as follows:

Fred — available hours: 40, personal estimated hours: 40, personal loading: 8 hours/day Mon to Fri

Mike — available hours: 40, personal estimated hours: 40, personal loading: 8 hours/day Mon to Fri

Case 2. Fred has been allowed 2 paid days off on Wednesday and Thursday in the middle of the task. As a result the work load picture will become as follows:

Fred — available hours: 24, personal estimated hours: 40, personal loading: 13.33 hours/day Mon, Tue, Fri (overloading)

Mike — available hours: 40, personal estimated hours: 40, personal loading: 8 hours/day Mon to Fri.

You can view the work load status by generating a resources report with the 'Resource Loading Report' radio button selected, as shown in the picture below where:

• Red squares denote work days with overloading (over 100% work hour allocation). The number of hours allocated for the day are indicated (10 in this case).
• Black squares mark days off, in this case Regular vacation type (see Vacation Calendar for details)
• Rose squares mark 'allocated' work days with 80.00 to 100.00% allocation. The number of hours allocated for the day are indicated (6 in this case).

Related Links: 

Activities

Creating activities in Activity Center

Manage dependencies

Activity dependency: Link column

Activity batch operations

Attaching files to activity

Parent activity progress calculation

Moving activity to another project

Resource loading