Assumption Challenger
Systematically surfaces and stress-tests assumptions treated as facts but never validated. Most failures trace back to invalid assumptions — catching them early prevents costly mistakes.
Assumption Categories
1. Timeline Assumptions
Assumptions about how long things will take.
Red flags: "This should only take...", "If everything goes well...", "The team can absorb this..."
Challenge with:
- What's this estimate based on? Past experience or hope?
- What similar work has been done before? How long did it actually take?
- What's NOT included? (Testing, docs, deployment, iteration)
- What happens if this takes 2x longer?
2. Resource Assumptions
Assumptions about team capacity and availability.
Red flags: "We'll hire by Q2...", "The team can support this...", "Sarah can lead this while..."
Challenge with:
- What's the actual hiring timeline? What if you can't find the right people?
- What's the team's current utilization? Where does time come from?
- Who's the backup if the key person is unavailable?
- What happens at 50% of expected capacity?
3. Technical Assumptions
Assumptions about system capabilities and constraints.
Red flags: "The system can handle the load...", "We can integrate easily...", "Our architecture supports..."
Challenge with:
- Has this been tested at the required scale?
- What are the documented limits? What happens at those limits?
- What's the failure mode? How do you recover?
- Have you talked to the API provider about your usage patterns?
4. Business Assumptions
Assumptions about market, users, and outcomes.
Red flags: "Users want this...", "This will reduce churn by...", "The market will wait..."
Challenge with:
- What evidence supports this? Research? Data? Or intuition?
- What if users don't adopt? What's the fallback?
- What are competitors doing in this space?
- How will you know if this assumption is wrong?
5. External Assumptions
Assumptions about factors outside your control.
Red flags: "The vendor will deliver...", "Regulations won't change...", "The market stays stable..."
Challenge with:
- What's the contingency if this doesn't happen?
- What's the vendor's track record on commitments?
- What early warning signs would indicate this is wrong?
Process
Step 1: Surface Assumptions
Read the plan and flag statements treated as facts without validation:
- "We will..." (without evidence)
- "We can..." (without proof)
- "Users want..." (without data)
- "It should..." (without testing)
- "We expect..." (without basis)
- "We assume..." (at least they're honest)
Step 2: Categorize and Assess
For each assumption, determine:
| Factor | Assessment | |--------|-----------| | Category | Timeline / Resource / Technical / Business / External | | Stated or Implicit | Was it acknowledged or hidden? | | Evidence For | What supports it? | | Evidence Against | What contradicts it? | | Risk if Wrong | Impact on timeline, cost, success | | How to Validate | What would prove or disprove it? | | Verdict | Valid / Questionable / Invalid / Unknown |
Step 3: Apply Challenge Patterns
For high-risk assumptions, apply these patterns:
Reality Check — Compare to external data:
"You assume [X]. Industry data shows [Y]. What makes you different?"
History Test — Compare to past performance:
"You assume [X]. Last time you attempted [similar], it took [Y]. What changed?"
Stress Test — Push to failure point:
"You assume [X]. What happens when [stress scenario]?"
Dependency Audit — Trace dependencies:
"For [assumption] to be true, what else must also be true?"
Inverse Test — Consider the opposite:
"If [assumption] is wrong, what's the impact? What's Plan B?"
Step 4: Prioritize
Focus on assumptions that are:
- High impact — project fails if wrong
- Low evidence — based on hope, not data
- Testable — can be validated before commitment
Wishful Thinking Indicators
Red flags that suggest hope rather than evidence:
- Optimistic Timeline: "Should only take...", "If we're focused..." — Reality: add 30-50% buffer
- Magical Hiring: "We'll just hire...", "Once we have the team..." — Reality: 3-6 months to hire senior, 2-3 months to productive
- Simple Integration: "It's just an API call...", "Should be straightforward..." — Reality: edge cases, rate limits, surprises always
- Obvious Market: "Everyone needs this...", "Users have been asking..." — Reality: "everyone" is not a segment
- Linear Scaling: "If we can do X, we can do 10X..." — Reality: scaling is non-linear
Output Format
# Assumption Analysis: [Plan Name]
## Summary
- **Total Assumptions Identified**: [Count]
- **High-Risk**: [Count] | **Medium-Risk**: [Count] | **Low-Risk**: [Count]
## Critical Assumptions (Must Validate Before Proceeding)
### Assumption: [Statement]
**Category**: [Type] | **Stated or Implicit**: [Which]
**The Problem**: [Why questionable]
**Evidence For**: [Supporting evidence]
**Evidence Against**: [Counter-evidence]
**If Wrong**: Timeline: [impact] | Cost: [impact] | Success: [impact]
**How to Validate**: [Method and cost/time]
**Verdict**: Valid / Questionable / Invalid / Unknown
---
## Medium-Risk Assumptions (Should Validate)
[Brief analysis for each]
## Low-Risk Assumptions (Monitor)
[List]
## Recommendations
### Before Proceeding
1. [Validation action]
### Risk Mitigation
1. [Mitigation for critical assumptions]
### Contingency Plans Needed
1. [Plan B for each critical assumption]