Product discovery & the four risks
In one sentence
Before building, check four risks: will they buy it, can they use it, can we build it, and does it work for the business?
The simple version
Marty Cagan says most product ideas fail. The best teams test ideas quickly before building them properly, looking at four risks: value (will people want it?), usability (can they figure it out?), feasibility (can we build it?) and viability (does it work for our business?).
Value
Will they buy or use it?
Usability
Can they figure it out?
Feasibility
Can we build it?
Viability
Does it work for the business?
Why it matters
It stops you spending months building features nobody uses.
How to do it
- 1Write the idea as a problem to solve, not a feature.
- 2Check value with customer conversations and fake-door tests.
- 3Check usability with a clickable prototype.
- 4Check feasibility with your engineers early.
- 5Check viability: legal, cost, sales, brand.
- 6Only then build it properly.
Real-world example
Before building a new reporting feature, a team shows a clickable mock-up to 8 customers, learns they only care about one chart, and builds that in a week.
What the books say
Tackle the big risks — value, usability, feasibility and business viability — before you build, not after.
Common mistakes
- Treating the roadmap as a list of promised features.
- Leaving engineers out of discovery.
- Testing only with colleagues.
Questions people ask
What's a fake-door test?
Showing a button or page for a feature that doesn't exist yet to see how many people click. It measures real interest cheaply.
References
- [1]
- [2]
More books on this in the library
Build: An Unorthodox Guide to Making Things Worth Making
Unorthodox product management guide for startups from Tony Fadell, covering processes for MVP building, team leadership, and product iteration based on iPod and Nest experiences. Key use cases include rapid prototyping and scaling hardware-software products. Offers a hands-on alternative to theoretical PM books like Inspired.
Sprint: How to Solve Big Problems and Test New Ideas in Just Five Days
Five-day product management sprint process for startups to build and test MVPs, validate ideas via prototyping and user feedback. Developed at Google Ventures for rapid problem-solving. Faster alternative to extended cycles in PM literature like Inspired.
Build: An Unorthodox Guide to Making Things Worth Making
A practical startup and product-building book by Tony Fadell that shares hard-won lessons from building world-changing products at Apple, Nest, and other ventures. It covers how to go from idea to product, lead teams, navigate investors, and make products that truly matter—highly relevant for startup founders learning to build and ship things people love.
Sprint: How to Solve Big Problems and Test New Ideas in Just Five Days
A practical guide to the Design Sprint methodology created at Google, offering a unique five-day process for solving tough problems and testing new ideas quickly.
Value Proposition Design: How to Create Products and Services Customers Want
Alexander Osterwalder's practical guide to designing compelling value propositions using the Value Proposition Canvas.
The Lean Product Playbook: How to Innovate with Minimum Viable Products and Rapid Customer Feedback
Dan Olsen's hands-on guide to building products customers love, providing a repeatable process for achieving product-market fit using lean startup principles.