From cto-team
Identifies and challenges implicit assumptions in roadmaps, architecture proposals, timelines, budgets, build vs buy decisions, and strategic initiatives to prevent project failures.
How this skill is triggered — by the user, by Claude, or both
Slash command
/cto-team:assumption-challengerThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
Systematically identifies and stress-tests assumptions that are treated as facts but may not be validated.
Systematically identifies and stress-tests assumptions that are treated as facts but may not be validated.
Most project failures trace back to invalid assumptions:
The cost of invalid assumptions compounds over time. A bad assumption in week 1 can waste months of work.
Assumptions about how long things will take.
Common patterns:
Challenge questions:
Assumptions about team capacity and availability.
Common patterns:
Challenge questions:
Assumptions about system capabilities and constraints.
Common patterns:
Challenge questions:
Assumptions about market, users, and business outcomes.
Common patterns:
Challenge questions:
Assumptions about factors outside your control.
Common patterns:
Challenge questions:
Read the proposal and identify statements that are treated as facts but aren't validated:
Flag statements containing:
For each assumption, categorize:
| Category | Risk if Wrong | Validation Difficulty |
|---|---|---|
| Timeline | Project delay | Medium (compare to past) |
| Resource | Execution failure | Medium (check market) |
| Technical | System failure | High (requires testing) |
| Business | Wasted investment | High (requires market validation) |
| External | Plans disrupted | Variable |
For each significant assumption:
### Assumption: [Statement]
**Category**: [Type]
**Stated or Implicit**: [Was it stated or hidden?]
**Evidence Supporting**:
- [Evidence 1]
- [Evidence 2]
**Evidence Against**:
- [Counter-evidence 1]
- [Counter-evidence 2]
**Risk if Wrong**:
- [Impact on timeline]
- [Impact on cost]
- [Impact on success]
**Validation Method**:
- [How to test this assumption]
- [Cost/time to validate]
**Verdict**:
[ ] Valid - Evidence supports
[ ] Questionable - Needs validation
[ ] Invalid - Evidence contradicts
[ ] Unknown - Cannot assess
Focus on assumptions that are:
Compare assumption to external data.
Template:
"You assume [X]. Industry data shows [Y]. What makes you different?"
Example:
"You assume you can hire 3 senior engineers in 2 months. The average time-to-hire for senior engineers in your market is 4-6 months. What's your strategy to beat that?"
Compare to organization's past performance.
Template:
"You assume [X]. Last time you attempted [similar thing], it took [Y]. What's changed?"
Example:
"You assume 8 weeks for the microservices migration. Your last infrastructure migration took 5 months. What's different this time?"
Push assumption to failure point.
Template:
"You assume [X]. What happens when [stress scenario]?"
Example:
"You assume the system handles 10K concurrent users. What happens during a flash sale with 50K? What's the failure mode?"
Trace assumption to its dependencies.
Template:
"For [assumption] to be true, what else must be true?"
Example:
"For your 6-week timeline to work, you need: (1) API specs finalized by week 1, (2) no scope changes, (3) 100% team availability, (4) no production incidents. How realistic is that?"
Consider what happens if assumption is wrong.
Template:
"If [assumption] is wrong, what's the impact? What's your Plan B?"
Example:
"If users don't adopt this feature, what's the fallback? Have you defined failure criteria?"
Red flags that suggest assumption is based on hope rather than evidence:
Reality: Things rarely go perfectly. Add 30-50% buffer.
Reality: Hiring takes 3-6 months for senior roles. Onboarding adds another 2-3 months to productivity.
Reality: Integrations always have edge cases, rate limits, and unexpected behaviors.
Reality: "Everyone" is not a market segment. Validate with actual user research.
Reality: Scaling is non-linear. What works at 10K users may fail at 100K.
When challenging assumptions, provide:
# Assumption Analysis: [Plan/Proposal Name]
## Summary
- **Total Assumptions Identified**: [Count]
- **High-Risk Assumptions**: [Count]
- **Requires Immediate Validation**: [Count]
## Critical Assumptions (Must Validate Before Proceeding)
### Assumption 1: [Statement]
**Category**: Timeline / Resource / Technical / Business / External
**Stated or Implicit**: Stated / Implicit
**The Problem**:
[Why this assumption is questionable]
**Evidence For**:
- [Supporting evidence]
**Evidence Against**:
- [Counter-evidence]
**If Wrong, Impact**:
- Timeline: [Impact]
- Budget: [Impact]
- Success: [Impact]
**How to Validate**:
- [Validation method]
- [Time required]
- [Cost]
**Verdict**: Valid / Questionable / Invalid / Unknown
---
### Assumption 2: [Statement]
[Same format]
---
## Medium-Risk Assumptions (Should Validate)
[List with brief analysis]
## Low-Risk Assumptions (Monitor)
[List]
## Recommendations
### Before Proceeding
1. [Validation action 1]
2. [Validation action 2]
### Risk Mitigation
1. [Mitigation for assumption 1]
2. [Mitigation for assumption 2]
### Contingency Plans Needed
1. [Plan B for assumption 1]
2. [Plan B for assumption 2]
The assumption-challenger skill feeds into the broader validation workflow:
Proposal/Plan
│
▼
[assumption-challenger] → List of assumptions with verdicts
│
▼
[antipattern-detector] → Identified anti-patterns
│
▼
[validation-report-generator] → Final 8-section report
npx claudepluginhub dave1362/claude-cto-teamIdentifies and challenges implicit assumptions in roadmaps, architecture proposals, timelines, budgets, build vs buy decisions, and strategic initiatives to prevent project failures.
Analyzes plans to surface hidden assumptions, rate confidence and impact, and identify critical vulnerabilities before execution.
Use this skill when the user asks to "map assumptions", "identify assumptions", "what are we assuming", "assumption audit", "what could go wrong with this idea", "test our assumptions", "what do we need to validate", "identify our riskiest assumption", or when reviewing an idea or PRD and wants to surface hidden bets before building. Do NOT use this skill for general risk analysis — that is part of the pre-mortem skill.