# identify-assumptions-existing

> Stress-test a feature idea for an existing product by surfacing risky assumptions across Value, Usability, Viability, and Feasibility using multi-perspective devil's advocate thinking.

- Skill: `phuryn/identify-assumptions-existing` (Agent Skill)
- Install (CLI): `npx skillmds add phuryn/identify-assumptions-existing`
- Raw SKILL.md: https://api.skillmd.com/api/skills/phuryn/identify-assumptions-existing/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Product & Planning, User Research
- Tags: Assumptions, Devils Advocate, Feature Validation, Product Discovery, Risk Analysis
- Author: phuryn (https://skillmd.com/u/phuryn)
- Updated: 2026-07-06
- Page: https://skillmd.com/skills/phuryn/identify-assumptions-existing

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## Identify Assumptions (Existing Product)

Devil's advocate analysis to surface risky assumptions across four risk areas.

### Context

You are stress-testing a feature idea for **$ARGUMENTS**.

If the user provides files (designs, PRDs, research), read them first.

### Instructions

The user will describe their product, objective, market segment, and feature idea. Work through these steps:

1. **Think from three perspectives** about why this feature might fail:
   - **Product Manager perspective**: Business viability, market fit, strategic alignment
   - **Designer perspective**: Usability, user experience, adoption barriers
   - **Engineer perspective**: Technical feasibility, performance, integration challenges

2. **Identify assumptions across four risk areas**:
   - **Value**: Will it create value for customers? Does it solve a real problem?
   - **Usability**: Will users figure out how to use it? Is the learning curve acceptable?
   - **Viability**: Can marketing, sales, finance, and legal support it?
   - **Feasibility**: Can it be built with existing technology? Are there integration risks?

3. **For each assumption**, note:
   - What specifically could go wrong
   - How confident you are (High/Medium/Low)
   - Suggested way to test it

Think step by step. Be thorough but constructive — the goal is to strengthen the idea, not kill it.

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### Further Reading

- [Assumption Prioritization Canvas: How to Identify And Test The Right Assumptions](https://www.productcompass.pm/p/assumption-prioritization-canvas)
- [How to Manage Risks as a Product Manager](https://www.productcompass.pm/p/how-to-manage-risks-as-a-product-manager)
- [Continuous Product Discovery Masterclass (CPDM)](https://www.productcompass.pm/p/cpdm) (video course)