Project Management guide · Risk, quality and control
Expert Judgment in Project Management: Uses and Techniques
Expert judgment is guidance based on the specialist knowledge or experience of people in a relevant field, used to support project decisions, estimates and plans. The PMBOK Guide lists it as a tool or technique in many of its processes; in British English it is also spelled 'expert judgement'.
Key takeaways
- Expert judgment draws on specialist knowledge to support decisions and estimates.
- Use structured techniques such as interviews, workshops and Delphi.
- Guard against optimism, anchoring and groupthink.
- Combine expert views with historical data wherever possible.
Where expert judgment is used
| Activity | Example of expert input |
|---|---|
| Initiation | Is the business case realistic? See feasibility study |
| Scope and requirements | What has been missed in the work breakdown structure? |
| Estimating | How long will this integration take? See cost estimation and effort estimation |
| Risk | What could go wrong, and how likely is it? See project risk |
| Procurement | Is this supplier's bid technically sound? |
| Quality | Which standards and tests apply? |
| Change control | What is the real impact of this change? |
Who counts as an expert
- Team members who have done similar work before.
- Specialists in other departments, such as legal, finance, security or procurement.
- Consultants, suppliers and industry bodies.
- Project managers and PMO staff with experience of similar projects.
- Users and customers, who are experts in how the work is actually done.
Expertise is specific. A brilliant architect is not necessarily an expert on software licensing.
Techniques for gathering expert judgment
| Technique | How it works | Best for |
|---|---|---|
| Interviews | One-to-one conversations with structured questions | Detailed or sensitive topics |
| Workshops | Facilitated group sessions | Risk identification, planning |
| Delphi technique | Anonymous rounds of estimates or opinions, shared and revised until views converge | Reducing dominance by senior voices |
| Nominal group technique | Individuals generate ideas silently, then share and vote | Prioritising options |
| Planning poker | Simultaneous reveal of estimates, then discussion | Agile estimation; see story points |
| Peer review | Experts review a plan, design or estimate | Quality and assurance |
Worked example: Delphi estimate
A project needs an estimate for migrating 40 reports to a new analytics platform. Four experts estimate anonymously.
- Round 1: 15, 25, 30 and 60 days. The facilitator shares the range and anonymised reasons. The 60-day expert noted that 12 reports use custom scripts.
- Round 2: after reading the reasons, estimates are 30, 35, 35 and 45 days.
- Result: the team uses a three-point estimate of 30 (optimistic), 35 (most likely) and 45 (pessimistic) days, which can feed a PERT calculation: (30 + 4 x 35 + 45) / 6 = 35.8 days.
- The custom-script concern is also logged as a risk.
Reducing bias
- Optimism bias: ask for ranges, and compare with actual results from past projects.
- Anchoring: collect estimates before sharing anyone else's.
- Groupthink and seniority: use anonymous methods like Delphi.
- Narrow expertise: combine several experts from different backgrounds.
- No record: write down who gave the judgment, the assumptions and the reasoning, so it can be checked later.
Expert judgment vs data-driven methods
Expert judgment is fastest when data is scarce or the work is new. Where historical data exists, combine it with methods such as analogous or parametric estimating, Monte Carlo simulation or throughput forecasting. A good practice is to use data as the starting point and experts to adjust for what is different this time.
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Frequently asked questions
What is expert judgment in project management?
Guidance based on the expertise of people with relevant knowledge or experience, used to inform decisions, estimates and plans.
Is it spelled expert judgment or expert judgement?
Both are correct. 'Judgment' is used in the PMBOK Guide; 'judgement' is common in British English outside legal contexts.
Where is expert judgment used in the PMBOK Guide?
It appears as a tool or technique in many processes, including developing the charter and plan, estimating, risk management and procurement.
What is the Delphi technique for expert judgment?
A method where experts give anonymous opinions over several rounds, seeing a summary of others' views each time, until their views converge.
What are the disadvantages of expert judgment?
It can be biased, inconsistent and hard to verify, and depends on finding the right experts.
How do you improve estimates based on expert judgment?
Ask for ranges, use several independent experts, collect estimates before discussion, record assumptions and compare with past actuals.
Is expert judgment the same as analogous estimating?
Not exactly. Analogous estimating uses data from similar past projects; expert judgment often draws on that experience but also includes opinion and interpretation.
Who can provide expert judgment?
Anyone with relevant specialist knowledge, including team members, other departments, suppliers, consultants, users and experienced project managers.
Is planning poker a form of expert judgment?
Yes. It is a consensus-based technique that draws on the team's own expertise.
Should expert judgment be documented?
Yes. Record who provided it, the assumptions and the reasoning, so it can be reviewed and learned from.
How is the nominal group technique used with expert judgment?
It is a structured way to gather and prioritise expert input: people generate ideas individually, share them in turn, discuss and then vote to prioritise.