Effort is the estimated time required to complete a project activity, expressed in minutes, hours, days, weeks, or months. The effort value is used - together with the start date of the activity - to calculate the planned end date-time. If a project calendar is linked, the calculation is based on working hours defined in that calendar. If no calendar is linked, effort is calculated using raw time (24/7).

For more information, see Defining the effort for project activities.