Activity Resource Estimating
Estimating schedule activity resources involves determining
what resources (persons, equipment, or materiel) and what quantities of each
resource will be used, and when each resource will be available to perform
project activities. The Activity Resource Estimating process is closely
coordinated with the Cost Estimating process (Section 7.1). For example:
A construction project team will need to be familiar with
local building codes. Such knowledge is often readily available from local
sellers. However, if the local labor pool lacks experience with unusual or
specialized construction techniques, the additional cost for a consultant might
be the most effective way to secure knowledge of the local building codes.
An automotive design team will need to be familiar with the
latest in automated assembly techniques. The requisite knowledge might be
obtained by hiring a consultant, by sending a designer to a seminar on robotics,
or by including someone from manufacturing as a member of the project team.
6-7. : Activity Resource Estimating: Inputs,
Tools & Techniques, and Outputs
Section 6.3.1 Activity Resource
.1 Enterprise Environmental Factors
The Activity Resource Estimating process uses the infrastructure
resource availability information included in enterprise environmental factors
.2 Organizational Process Assets
Organizational process assets (Section 22.214.171.124) provide the policies
of the performing organization regarding staffing and the rental or purchase of
supplies and equipment that are considered during activity resource estimating.
If available, historical information regarding what types of resources were
required for similar work on previous projects are reviewed.
.3 Activity List
The activity list (Section 126.96.36.199) identifies the schedule activities for
resources that are estimated.
.4 Activity Attributes
The activity attributes (Section 188.8.131.52) developed during the
activity definition process provide the primary data input for use in estimating
those resources required for each schedule activity in the activity list.
.5 Resource Availability
Information on which resources (such as people, equipment, and
materiel) are potentially available (Sections 184.108.40.206 and 220.127.116.11) is used
for estimating the resource types. This knowledge includes consideration of
various geographical locations from which the resources originate and when they
may be available. For example, during the early phases of an engineering design
project, the pool of resources might include junior and senior engineers in
large numbers. During later phases of the same project, however, the pool can be
limited to those individuals who are knowledgeable about the project as a result
of having worked on the earlier phases of the project.
.6 Project Management Plan
The schedule management plan is a component part of the
project management plan (Section 4.3) that is used in Activity Resource Estimating.
Section 6.3.2 Activity Resource
Estimating: Tools and Techniques
.1 Expert Judgment
Expert judgment is often required to assess the resource-related
inputs to this process. Any group or person with specialized knowledge in
resource planning and estimating can provide such expertise.
.2 Alternatives Analysis
Many schedule activities have alternative methods of
accomplishment. They include using various levels of resource capability or
skills, different size or type of machines, different tools (hand versus
automated), and make-or-buy decisions regarding the resource (Section 18.104.22.168).
.3 Published Estimating Data
Several companies routinely publish updated production rates and
unit costs of resources for an extensive array of labor trades, materiel, and
equipment for different countries and geographical locations within countries.
.4 Project Management Software
Project management software has the capability to help plan,
organize, and manage resource pools and develop resource estimates. Depending
upon the sophistication of the software, resource breakdown structures, resource
availabilities, and resource rates can be defined, as well as various resource
.5 Bottom-up Estimating
When a schedule activity cannot be estimated with a
reasonable degree of confidence, the work within the schedule activity is
decomposed into more detail. The resource needs of each lower, more detailed
piece of work are estimated, and these estimates are then aggregated into a
total quantity for each of the schedule activity’s resources. Schedule
activities may or may not have dependencies between them that can affect the
application and use of resources. If there are dependencies, this pattern of
resource usage is reflected in the estimated requirements of the schedule
activity and is documented.
Section 6.3.3 Activity Resource
.1 Activity Resource Requirements
The output of the Activity Resource Estimating process is an
identification and description of the types and quantities of resources required
for each schedule activity in a work package. These requirements can then be
aggregated to determine the estimated resources for each work package. The
amount of detail and the level of specificity of the resource requirement
descriptions can vary by application area. The resource requirements
documentation for each schedule activity can include the basis of estimate for
each resource, as well as the assumptions that were made in determining which
types of resources are applied, their availability, and what quantity are used.
The Schedule Development process (Section 6.5) determines when the resources are needed.
.2 Activity Attributes (Updates)
The types and quantities of resources required for each schedule
activity are incorporated into the activity attributes. If approved change
22.214.171.124) result from the Activity Resource Estimating process, then the
activity list (Section 126.96.36.199) and activity attributes (Section 188.8.131.52)
are updated to include those approved changes.
.3 Resource Breakdown Structure
The resource breakdown structure (RBS) is a hierarchical structure
of the identified resources by resource category and resource type.
.4 Resource Calendar (Updates)
A composite resource calendar for the project documents working
days and nonworking days that determine those dates on which a specific
resource, whether a person or materiel, can be active or is idle. The project
resource calendar typically identifies resource-specific holidays and resource
availability periods. The project resource calendar identifies the quantity of
each resource available during each availability period.
.5 Requested Changes
The Activity Resource Estimating process can result in
requested changes (Section 184.108.40.206) to add or delete planned schedule activities
within the activity list. Requested changes are processed for review and
disposition through the Integrated Change Control process (Section 4.6).