Page 193 -

6 - PROJECT TIME MANAGEMENT

Estimating activity durations uses information on activity scope of work, required resource types, estimated
resource quantities, and resource calendars. The inputs of the estimates of activity duration originate from the
person or group on the project team who is most familiar with the nature of the work in the specific activity. The
duration estimate is progressively elaborated, and the process considers the quality and availability of the input
data. For example, as more detailed and precise data is available about the project engineering and design work,
the accuracy of the duration estimates improves. Thus, the duration estimate can be assumed to be progressively
more accurate and of better quality.

The Estimate Activity Durations process requires an estimation of the amount of work effort required to complete
the activity and the amount of available resources estimated to complete the activity. These estimates are used to 6
approximate the number of work periods (activity duration) needed to complete the activity using the appropriate
project and resource calendars. All data and assumptions that support duration estimating are documented for
each estimate of activity duration.

6.5.1 Estimate Activity durations: Inputs

6.5.1.1 Schedule Management Plan

Described in Section 6.1.3.1. The schedule management plan defines the method used and the level of accuracy
along with other criteria required to estimate activity durations including the project update cycle.

6.5.1.2 Activity List

Described in Section 6.2.3.1. The activity list identifies the activities that will need duration estimates.

6.5.1.3 Activity Attributes

Described in Section 6.2.3.2. The activity attributes provide the primary data input for use in estimating durations
required for each activity in the activity list.

6.5.1.4 Activity resource requirements

Described in Section 6.4.3.1. The estimated activity resource requirements will have an effect on the duration of
the activity, since the level to which the resources assigned to the activity meet the requirements will significantly
influence the duration of most activities. For example, if additional or lower-skilled resources are assigned to an
activity, there may be reduced efficiency or productivity due to increased communication, training, and coordination
needs leading to a longer duration estimate.

©2013 Project Management Institute. A Guide to the Project Management Body of Knowledge (PMBOK Guide) – Fifth Edition 167
®

Licensed To: Jorge Diego Fuentes Sanchez PMI MemberID: 2399412
This copy is a PMI Member benefit, not for distribution, sale, or reproduction.