In project management, accurate reporting on schedule progress entails documentation of the remaining duration of each schedule activity. In schedule reporting, this term is used when referring to work that is currently in progress. The time remaining for an activity is calculated from the date that the report is created (the “data date” or “as of” date).
The remaining duration is defined as the number of calendar units between the date the report is generated and the current (expected) finish dates for the activities in question. This information is often displayed as a bar graph that also shows the actual start dates of the schedule activities. This type of project management “snapshot” report makes it possible to visually assess the percentage of work completed and the estimated percentage remaining. This information is often helpful for ongoing human resource planning. It can be used to calculate an estimate of how many labor hours are required for completion of a current schedule activity.
Calendar units are used rather than days to provide the greatest level of accuracy in remaining duration reports. A calendar unit may represent a workday, a shift, a work hour, or any other time unit that is relevant to the nature of the project. This includes only units during which work is actually performed and not times when the schedule activities are idle (weekends, nights, holidays, etc) unless otherwise specified. This means it is important not to confuse the number of units remaining with the number of actual days. For example, if 10 calendar units are left in the duration of an activity, this might represent 80 total hours of work done between Monday and Friday on two consecutive weeks. So, the actual date of completion might be 14 days in the future rather than 10 days.
This project management term is defined in the 3rd edition of the PMBOK, but not in the 4th.