9.2 Estimate Activity Resources

Work out how many people and how much material each activity needs.

Planning / Resource · ← PMBOK reference · See it on the map

Why it matters

Understaffing an activity means it slips; overstaffing it wastes budget that could have covered a different gap elsewhere in the project.

What done looks like

Every activity carries a resource estimate with its basis recorded.

First time tip

Estimate resources at the same time you estimate duration, not afterward. The two numbers depend on each other and drift apart if done separately.

What you need (Inputs)

• Resource Management Plan
  How Scrum/Kanban projects satisfy this — counted from: project roles (driftless/models/agile.py:ProjectRole) — naming who holds each agile role (product owner, Scrum Master, developer, stakeholder proxy) is how an agile team plans its resources, in place of the stored prose plan a predictive project writes
• Scope Baseline
  How Scrum/Kanban projects satisfy this — counted from: committed backlog items and definition-of-done items (models/agile.py) — a committed backlog (status ready/in_progress/done) plus a written definition of done is what an agile team baselines scope against
• Activity List
• Activity Attributes
• Assumption Log
• Cost Estimates
• Resource Calendars
• Risk Register

How you do it (Tools & Techniques)

• Expert Judgment
• Bottom Up Estimating
• Analogous Estimating
• Parametric Estimating
• Data Analysis
• Project Management Information System

What you get (Outputs)

• Resource Requirements
• Basis of Estimates
• Resource Breakdown Structure

Worked example

Repainting the reading room is estimated at two painters for three days, 30 litres of paint and one scaffold. The scaffold is the number that matters: only one is available locally that week, so the estimate and the schedule have to agree.

Common pitfalls

• Estimating the people and forgetting the materials and equipment.
• Estimating resources after durations, so the two numbers disagree.
• Recording a resource number with no basis anyone can question.

How driftless helps

• Bottom Up Estimating can be run here.
• Analogous Estimating can be run here.
• Parametric Estimating can be run here.
• Basis of Estimates can be created in the wizard.
• Resource Breakdown Structure can be created in the wizard.