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Route to the right mental model based on your domain and problem type. The single entry point for all thinking skills.
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Based on SOC occupation classification
Use when a search or investigation could run indefinitely and you need a stopping rule. Set an explicit "good enough" threshold and stop at the first option that clears it.
Start with means, not goals; co-create with partners; leverage contingencies. Use for startup strategy, innovation projects, and uncertain/novel domains where planning is unreliable.
When a constraint is treated as fixed ("too expensive", "impossible", "always done this way"), ask whether it's physics or just convention, then rebuild from what's actually true.
Deciding what to build or why a feature isn't adopted. Reframe from features to the "job" users hire the product for — the progress they seek — to prioritize and position.
Use when a defect is selective (some endpoints/regions/users/times affected, not all) and the cause is unclear — map what IS vs IS-NOT affected; the boundary contrast points at the root cause.
Use when picking where to intervene in a system and tuning parameters keeps not sticking—rank candidate interventions by Meadows' hierarchy and choose the highest-leverage point you can move.
| name | thinking-model-router |
| description | Route to the right mental model based on your domain and problem type. The single entry point for all thinking skills. |
This is the master routing skill for all mental models. Instead of knowing 38 frameworks, start here. Identify your domain and problem type, and this skill points you to the right model(s). Think of it as the "which tool do I use?" guide.
Core Principle: Don't memorize models—memorize how to find the right one. Domain + Problem Type → Model.
If you already know the right model, invoke it directly — don't route. This skill is for when you're unsure which model fits. If the problem obviously calls for a specific model (e.g., "where's the bottleneck?" → theory-of-constraints; "how would an attacker break this?" → red-team), go straight to it. Routing is overhead you only pay when the match isn't obvious. Likewise, if no model clearly helps, just reason directly — don't force one.
| Domain | You're working on... |
|---|---|
| Coding/Debugging | Bugs, errors, performance issues, root cause |
| Architecture | System design, technical decisions, scalability |
| Product | Features, user needs, prioritization, roadmap |
| Business Strategy | Competition, growth, market, organization |
| Personal Decisions | Career, life choices, major commitments |
| Abstract/Analytical | Arguments, ideas, theories, pure reasoning |
| Risk/Safety | What could go wrong, preparation, resilience |
| Innovation | New ideas, breakthroughs, creative solutions |
| Type | You need to... |
|---|---|
| Diagnose | Find root cause, understand why |
| Decide | Choose between options |
| Understand | Grasp how something works |
| Create | Generate new solutions |
| Evaluate | Judge quality or validity |
| Predict | Forecast outcomes |
| Optimize | Improve performance |
PROBLEM → MODEL(S)
─────────────────────────────────────────────────────
Bug with unknown cause → Scientific Method, 5 Whys Plus
Performance degradation → Theory of Constraints, Systems Thinking
Spans multiple services → Systems Thinking, Feedback Loops
Incident postmortem → 5 Whys Plus, Systems Thinking
Flaky/intermittent behavior → Scientific Method (hypothesis testing)
"It works on my machine" → Map-Territory (model vs reality gap)
Default for debugging: Start with 5 Whys Plus, escalate to Systems Thinking if it spans components.
PROBLEM → MODEL(S)
─────────────────────────────────────────────────────
Technology choice → Lindy Effect, Reversibility
Build vs buy → Opportunity Cost, First Principles
Scalability design → Systems Thinking, Leverage Points
Microservices vs monolith → Cynefin, Reversibility
Database selection → Lindy Effect, Theory of Constraints
API design tradeoffs → TRIZ (resolve contradictions)
Should we rewrite? → Second-Order, Opportunity Cost
Default for architecture: Start with Reversibility (is this Type 1 or Type 2?), then Systems Thinking for interconnections.
PROBLEM → MODEL(S)
─────────────────────────────────────────────────────
What should we build? → Jobs to be Done
Feature prioritization → Opportunity Cost, Theory of Constraints
Why aren't users engaging? → Jobs to be Done, 5 Whys Plus
New product exploration → Effectuation, First Principles
Should we pivot? → Regret Minimization, Reversibility
Product-market fit → Jobs to be Done, Bayesian
Roadmap planning → Theory of Constraints, Opportunity Cost
A/B test interpretation → Bayesian, Probabilistic
Default for product: Start with Jobs to be Done (what job is the user hiring this for?).
PROBLEM → MODEL(S)
─────────────────────────────────────────────────────
Competitive analysis → Red Team, Second-Order
Market entry → Cynefin, Effectuation
Growth strategy → Feedback Loops, Leverage Points
Organizational dysfunction → Archetypes, Systems Thinking
Resource allocation → Theory of Constraints, Opportunity Cost
Startup strategy → Effectuation, Margin of Safety
M&A evaluation → Pre-mortem, Steel-manning
Pricing decisions → First Principles, Fermi Estimation
Default for strategy: Start with Cynefin (what domain is this problem in?), then match approach.
PROBLEM → MODEL(S)
─────────────────────────────────────────────────────
Should I take this job? → Regret Minimization, Reversibility
Career direction → Circle of Competence, Regret Minimization
Major life decision → Regret Minimization, Pre-mortem
Learning what to learn → Circle of Competence, Lindy Effect
Negotiation prep → Steel-manning, Red Team
Should I start a company? → Effectuation, Margin of Safety, Pre-mortem
Time allocation → Opportunity Cost, Theory of Constraints
Default for personal: Start with Regret Minimization (what will 80-year-old you think?).
PROBLEM → MODEL(S)
─────────────────────────────────────────────────────
Evaluating an argument → Steel-manning, Bayesian
Challenging assumptions → First Principles, Socratic
Estimating unknowns → Fermi Estimation, Probabilistic
Updating beliefs → Bayesian, Probabilistic
Exploring edge cases → Thought Experiment, Inversion
Finding logical flaws → Inversion, Steel-manning
Complex causation → Systems Thinking, Feedback Loops
Philosophical questions → Thought Experiment, First Principles
Default for abstract: Start with Steel-manning (argue the strongest opposing view first).
PROBLEM → MODEL(S)
─────────────────────────────────────────────────────
What could go wrong? → Pre-mortem, Red Team
Security review → Red Team, Inversion
Disaster preparation → Pre-mortem, Margin of Safety
Avoiding catastrophic failure → Margin of Safety, Via Negativa
Stress-testing plans → Red Team, Pre-mortem
Probability of failure → Probabilistic, Bayesian
Building resilience → Via Negativa, Margin of Safety
Default for risk: Start with Pre-mortem (assume failure, explain why).
PROBLEM → MODEL(S)
─────────────────────────────────────────────────────
Breakthrough needed → First Principles, TRIZ
Stuck on contradictions → TRIZ
Limited resources → Effectuation, Via Negativa
Simplification → Via Negativa, Occam's Razor
Challenging "impossible" → First Principles, TRIZ
New market creation → Effectuation, Jobs to be Done
Removing complexity → Via Negativa, Occam's Razor
Default for innovation: Start with First Principles (strip to fundamentals, rebuild).
┌─────────────────────────────────────────────────────────────────┐
│ MENTAL MODEL QUICK ROUTER │
├─────────────────────────────────────────────────────────────────┤
│ │
│ "Why is this broken?" → 5 Whys Plus, Scientific Method │
│ "How does this system work?" → Systems Thinking, Feedback Loops│
│ "What should we build?" → Jobs to be Done │
│ "Should I do this?" → Reversibility, Regret Min │
│ "What could go wrong?" → Pre-mortem, Red Team │
│ "How do I innovate?" → First Principles, TRIZ │
│ "What's the probability?" → Bayesian, Probabilistic │
│ "Where's the bottleneck?" → Theory of Constraints │
│ "What am I giving up?" → Opportunity Cost │
│ "Is this argument valid?" → Steel-manning │
│ "Will this technology last?" → Lindy Effect │
│ "How complex is this?" → Cynefin │
│ "What to remove?" → Via Negativa │
│ "Is this safe enough?" → Margin of Safety │
│ │
└─────────────────────────────────────────────────────────────────┘
START HERE
│
▼
┌─────────────────────┐
│ What's your domain? │
└──────────┬──────────┘
│
┌─────┴─────┬──────────┬──────────┬──────────┐
▼ ▼ ▼ ▼ ▼
Coding Architecture Product Strategy Personal
│ │ │ │ │
▼ ▼ ▼ ▼ ▼
┌─────────────────────┐
│ What problem type? │
│ Diagnose/Decide/ │
│ Understand/Create/ │
│ Evaluate/Predict │
└──────────┬──────────┘
│
▼
┌─────────────────────┐
│ Look up in domain │
│ table above │
└──────────┬──────────┘
│
▼
┌─────────────────────┐
│ Single model enough?│
└──────────┬──────────┘
│
┌──────┴──────┐
▼ ▼
YES NO
│ │
▼ ▼
Apply it Use Model Combination
(Sequential/Parallel/Nested)
5 Whys Plus - Iterative "why" with bias guardsScientific Method - Hypothesis → Test → LearnKepner-Tregoe - Systematic problem/decision analysisReversibility - Type 1 vs Type 2 decisionsRegret Minimization - What will future-you think?Opportunity Cost - What are you giving up?Bayesian - Update beliefs with evidenceProbabilistic - Calibrated probability estimatesSystems Thinking - Feedback, emergence, non-linearityFeedback Loops - Reinforcing and balancing loopsTheory of Constraints - Find and exploit the bottleneckLeverage Points - Where small changes have big effectsArchetypes - Recurring system patternsPre-mortem - Assume failure, explain whyRed Team - Attack your own planMargin of Safety - Build in buffersInversion - Identify paths to failure, avoid themFirst Principles - Strip to fundamentals, rebuildTRIZ - Resolve technical contradictionsEffectuation - Start with means, not goalsVia Negativa - Improve by removingSteel-manning - Argue strongest opposing viewLindy Effect - Older = likely to last longerCircle of Competence - Know your expertise boundariesOccam's Razor - Prefer simpler explanationsCynefin - Clear/Complicated/Complex/Chaotic domainsModel Selection - Choose the right modelModel Combination - Use multiple models togetherJobs to be Done - What job is user hiring this for?Thought Experiment - Structured imaginationFermi Estimation - Order-of-magnitude calculationsUse Model Combination when:
| Situation | Combination Pattern | Example |
|---|---|---|
| High-stakes decision | Sequential | Reversibility → Pre-mortem → Opportunity Cost |
| System diagnosis | Nested | Cynefin (macro) → ToC (meso) → OODA (micro) |
| Validating strategy | Parallel | Red Team + Steel-manning + Second-Order |
| Innovation under constraints | Sequential | First Principles → TRIZ → Effectuation |
| Career decision | Temporal | 5 Whys (past) → Circle of Competence (present) → Regret Min (future) |
# Model Router Analysis
## Context
Domain: [Coding/Architecture/Product/Strategy/Personal/Abstract/Risk/Innovation]
Problem: [Brief description]
Problem Type: [Diagnose/Decide/Understand/Create/Evaluate/Predict/Optimize]
## Routed Models
Primary: [Main model to use]
Secondary: [If needed]
Combination pattern: [Sequential/Parallel/Nested/None]
## Application
[Apply the selected model(s) here]
## Verification
- [ ] Domain correctly identified
- [ ] Problem type matches
- [ ] Model fits the situation
- [ ] Considered if combination needed
Remember: You don't need to know all 38 models. You need to know how to find the right one. Start with domain, identify problem type, look it up, apply. That's it.