Identify risky assumptions for a feature idea in an existing product across Value, Usability, Viability, and Feasibility. Uses multi-perspective devil's advocate thinking. Use when stress-testing a feature idea, doing risk assessment, or preparing for assumption mapping.
Install with the open skills CLI (global, non-interactive — available in every Claude Code session):
npx skills add phuryn/pm-skills --skill "identify-assumptions-existing" -g -a claude-code -yOr manually — copy the SKILL.md below into:
~/.claude/skills/identify-assumptions-existing/SKILL.md---
name: identify-assumptions-existing
description: "Identify risky assumptions for a feature idea in an existing product across Value, Usability, Viability, and Feasibility. Uses multi-perspective devil's advocate thinking. Use when stress-testing a feature idea, doing risk assessment, or preparing for assumption mapping."
---
## 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.
---
### 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)
You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation.
Use when you have a written implementation plan to execute in a separate session with review checkpoints
Use when executing implementation plans with independent tasks in the current session