Is “Wideband Delphi” a secret weapon for PMs for Accurate Estimations ?

5 min read2 days ago

You are in a meeting, presenting the estimated timeline for a critical product feature. Your developers are hesitant, stakeholders are pushing for a faster release, and the last time this happened, you missed the deadline by months. What if there was a structured way to get more accurate estimates without bias and guesswork? Enter Wideband Delphi — a collaborative estimation technique that’s a game-changer for PMs.

The Estimation Challenge in Product Management

As a Product Manager (PM), you’ve likely encountered estimation nightmares:

Underestimation leads to unrealistic expectations, causing product delays and stakeholder frustration.
Overestimation can slow down the product roadmap, affecting competitiveness.
Cognitive biases (anchoring, groupthink, optimism bias) distort estimates, making them unreliable.

This is where Wideband Delphi comes in — a structured, expert-driven method to refine estimations iteratively.

What is Wideband Delphi?

Wideband Delphi is an iterative consensus-building technique for improving estimation accuracy through multiple expert reviews. Unlike a single-round estimation method (like Planning Poker), it involves repeated discussions, refining estimates at each stage.

This technique is an enhancement of the Delphi method, originally developed at RAND Corporation in the 1950s to predict military outcomes. It was later adapted for project estimation in software development and product management.

How Wideband Delphi Works

It follows a structured process:

Identify Experts — Select a diverse group of experts (developers, designers, QA engineers, etc.).
Define the Scope — Clearly outline the task or feature to be estimated.
Conduct the First Round of Estimation — Each expert individually provides estimates based on their knowledge.
Facilitate Anonymous Discussions — A moderator (often the PM) compiles the estimates anonymously and shares them with the group.
Iterate & Refine — Experts discuss anonymously, revise their estimates, and repeat until a consensus is reached.
Finalize the Estimate — Once estimates converge, the team agrees on a final estimation.

Example — Estimating a Complex Feature for a FinTech App

You’re a Product Manager at a FinTech startup working on a “One-Tap Investment” feature — allowing users to invest in stocks with a single click. This involves:

Backend API enhancements
Frontend UI changes
Security & compliance checks

Step 1: Gather Experts

You invite:

A senior backend engineer
A frontend engineer
A security specialist
A QA engineer
A data analyst

Step 2: Initial Estimates

Each expert provides an estimate individually:

Backend: 6 weeks
Frontend: 3 weeks
Security: 8 weeks
QA: 4 weeks
Data Analysis: 2 weeks

There’s a huge variance in estimates, indicating different levels of understanding.

Step 3: Anonymous Discussion & Justification

The backend engineer realizes they forgot to factor in API throttling.
The security specialist overestimated compliance needs.
The frontend engineer identifies reusable components, reducing work.

Step 4: Revised Estimates

After discussion and adjustments:

Backend: 7 weeks
Frontend: 2 weeks
Security: 6 weeks
QA: 4 weeks
Data Analysis: 2 weeks

Step 5: Final Consensus

The team aligns on an 8-week timeline, balancing risks and resource constraints.

Had the PM gone with the first estimates, they would have projected anywhere between 6 to 15 weeks. Wideband Delphi brought clarity and reduced variance, ensuring a realistic delivery timeframe.

Pros & Cons of Wideband Delphi for Product Managers

✅ Pros

✔ Reduces Bias — Experts provide estimates independently, avoiding anchoring bias.
✔ Increases Accuracy — Iterative refinement improves precision.
✔ Encourages Collaboration — Experts across functions align on scope and feasibility.
✔ Improves Risk Awareness — Discussions highlight hidden complexities early.
✔ Boosts Stakeholder Confidence — A well-structured process builds trust in estimates.

❌ Cons

❌ Time-Consuming — Multiple rounds of discussion take time, making it unsuitable for quick estimates.
❌ Requires a Skilled Moderator — A weak facilitator might lead to inefficient discussions.
❌ Expert Availability Matters — If key contributors aren’t available, the method fails.
❌ Not Ideal for Small Tasks — It’s overkill for simple or low-risk estimations.

When Should Product Managers Use Wideband Delphi?

✅ Best for:
✔ Estimating complex features with multiple dependencies
✔ New, unfamiliar projects where historical data is lacking
✔ High-risk initiatives (e.g., regulatory changes, security updates)
✔ Roadmap planning that requires executive buy-in

🚫 Avoid if:

The task is straightforward (use simpler techniques like T-shirt sizing).
A tight deadline requires a quick estimate.

Pro Tips for Product Managers Using Wideband Delphi

✔ Predefine the Estimation Criteria — Clearly state what “done” means to avoid misunderstandings.
✔ Timebox Discussions — Prevent endless debates by limiting each round’s discussion.
✔ Encourage Honest Inputs — Emphasize that estimations should be realistic, not aspirational.
✔ Use Estimation Tools — Tools like Miro, Jira, or Excel can streamline the process.
✔ Follow Up — Track how actual delivery compares to estimates for continuous improvement.

Final Thoughts!

As a Product Manager, estimation is your superpower. Wideband Delphi helps you navigate uncertainty, align teams, and build realistic roadmaps. By leveraging expert consensus, you ensure that your estimates are not just guesses but well-informed projections.

Thanks for reading! If you’ve got ideas to contribute to this conversation please comment. If you like what you read and want to see more, clap me some love! Follow me here, or connect with me on LinkedIn or Twitter.

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