project management glossary

duration

 The number of time units (not including holidays or other non-working periods) required to complete an activity or other project element. Usually expressed as work days or work weeks.

 The length of time (calendar elapsed time) needed to complete an activity.

 The calendar time it takes to create a deliverable.

 The actual amount of time that passes before a task is done. Duration equals work divided by resource effort.

 The planned or actual elapsed time between two events, e.g. between the start and finish of an activity, between two milestones or the whole project. Duration may be measured in units of calendar time, or project calendar time. It can be misleading to measure it in days worked on an activity since calendar and working time may pass with no production. It is totally wrong to measure duration in man-hours or man-days which are units of work, not time.

duration calculation

 The calculation of time required to complete an activity.

duration compression

 Shortening the project schedule without reducing the project scope. Duration compression is not always possible and often requires an increase in project cost.