- Duration estimates are just that, estimates. The activities will occur in the future and there are no facts about the future.
- ~ David Hulett
The activity duration estimates are created by the estimate activity durations process. Based on other information such as the resource breakdown structure and resource calendars as well as other information about the activities, the project team develops estimates of how long each activity will take. For instance, the organization's holiday schedule (resource calendar), availability of skilled staff, and other time requirements (such as how long it takes the concrete to dry before it is ready for the next activity) are considered.
The estimates are used to develop the schedule, and they may also feed into the process to identify risks. The estimates can feed into the schedule allowances. And the expert judgment used to make the estimates can also help identify risks. For instance, cement may cure (dry) at a certain rate based on the temperature. If the weather is colder than expected, it may take longer (risk to the schedule).