Process: Estimate Activity Resources
Process Group: Planning
Knowledge Area: Project Resource Management
Purpose
The Estimate Activity Resources process involves estimating the type and quantity of resources—both human and physical—needed to perform each project activity. It informs schedule development, cost estimation, and procurement planning.
Inputs
- Project Management Plan – Especially the resource management plan and scope baseline.
- Project Documents – Includes activity list, activity attributes, assumption log, cost estimates, and risk register.
- Enterprise Environmental Factors (EEFs) – Resource availability, team skills, location constraints, labor rates.
- Organizational Process Assets (OPAs) – Historical data, resource estimation policies, and lessons learned.
Tools and Techniques
- Expert Judgment – Used to estimate based on experience with similar activities or resource requirements.
- Bottom-Up Estimating – Estimates resources at the activity level and aggregates upward.
- Analogous Estimating – Uses historical data from similar tasks to estimate resource needs.
- Parametric Estimating – Uses statistical relationships (e.g., square footage per labor hour).
- Data Analysis – Includes alternatives analysis to compare resource options and trade-offs.
- Project Management Information System (PMIS) – Tools that assist with estimating and resource modeling.
- Meetings – Planning sessions to validate estimates and review constraints with stakeholders.
Outputs
- Resource Requirements – Type and amount of each resource needed per activity, including personnel, equipment, and materials.
- Basis of Estimates – Documentation of assumptions, methods, data sources, and confidence levels for each estimate.
- Resource Breakdown Structure (RBS) – A hierarchical list of resource types by category and function.
- Project Document Updates – Updates to activity attributes, assumption log, and lessons learned register.
Role in the Process Group and Knowledge Area
- Within the Planning Process Group, this process ensures activities are supported with realistic and feasible resource assumptions.
- As part of Project Resource Management, it informs downstream processes like acquiring resources, estimating duration, and cost planning.
Why It Matters
- Supports Realistic Scheduling – Accurate resource estimates help define achievable timelines.
- Informs Cost Estimating – Resource usage drives labor and material costs.
- Improves Planning Accuracy – Helps avoid over- or under-staffing and resource bottlenecks.
- Aligns Stakeholder Expectations – Clarifies what is needed, when, and from whom.