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Scenario Planning & Modeling

Plan for different outcomes and make informed decisions with scenario analysis and sensitivity modeling.

Why Scenario Planning Matters

The future is uncertain. No matter how carefully you forecast, actual results will differ from your projections. Scenario planning helps you:

Understand Risk

See what happens if things go wrong. How much runway do you have if growth slows? When do you need to cut costs?

Identify Opportunities

Explore upside cases. What resources do you need to capture faster growth? When should you hire aggressively?

Make Better Decisions

Test assumptions before committing. Should you expand to a new market? Is it worth building that new feature?

Communicate with Stakeholders

Show investors and board members you've thought through different outcomes. Build confidence in your planning.

The Three-Scenario Framework

The most common approach is to build three scenarios representing different possible futures:

Best Case (Upside)

Things go better than expected. Strong product-market fit, efficient marketing, good market conditions.

Typical Assumptions:
  • • Revenue: 20-30% higher than base
  • • Conversion rates: 20-50% improvement
  • • Churn: 20-30% lower than base
  • • CAC: 20-30% more efficient
  • • Margins: Improved due to economies of scale

Use this to: Plan for success. How much capital do you need to capture the opportunity? When should you invest ahead of growth?

Base Case (Most Likely)

Your realistic, central expectation. This should be achievable but not sandbagged.

Build This From:
  • • Historical performance trends
  • • Validated assumptions from customer data
  • • Reasonable market growth rates
  • • Confirmed hiring and investment plans

Use this to: Set targets, budget resources, and communicate primary expectations to your team and investors.

Worst Case (Downside)

Things go worse than expected. Slower growth, market headwinds, operational challenges.

Typical Assumptions:
  • • Revenue: 20-40% lower than base
  • • Conversion rates: Significantly worse
  • • Churn: 30-50% higher than base
  • • CAC: 30-50% less efficient
  • • Costs: Same or higher (can't cut fast enough)

Use this to: Understand risks. How long does your runway last? What's your contingency plan? When do you need to make hard decisions?

Sensitivity Analysis

Test how changes in individual variables affect your outcomes. Identify which assumptions matter most.

How to Do Sensitivity Analysis:

1
Identify Key Drivers

Pick 3-5 assumptions that have the biggest impact on your business. Examples: conversion rate, churn rate, average contract value, marketing spend efficiency.

2
Vary Each Assumption

Change each variable by ±10%, ±20%, ±30% while keeping others constant. See how revenue, profitability, and cash flow respond.

3
Create a Sensitivity Table

Document how outcomes change with each input. This shows which levers have the most impact and deserve the most attention.

Example: SaaS Company
Variable-20%Base+20%Impact
Conversion Rate$800K ARR$1M ARR$1.2M ARRHigh
Churn Rate$1.1M ARR$1M ARR$900K ARRMedium
Avg Price$900K ARR$1M ARR$1.1M ARRMedium

This shows conversion rate has the biggest impact on ARR, so that's where to focus improvement efforts.

What-If Modeling

Test specific decisions or events to understand their impact:

Strategic Decisions

  • Hiring: What if we hire 5 engineers in Q2 vs Q3? Impact on cash, product velocity, revenue.
  • Pricing: What if we increase prices 20%? Model churn impact vs revenue increase.
  • New Product: What if we launch a premium tier? Model development costs, take rate, and revenue potential.
  • Market Expansion: What if we enter Europe? Model localization costs, conversion rates, CAC differences.

External Events

  • Recession: What if sales cycles double and budgets contract 30%? Model pipeline delays and revenue impact.
  • Competitor: What if a major competitor slashes prices? Model defensive pricing moves and margin pressure.
  • Regulatory: What if new compliance requirements add $200K in costs? Model timing and impact on margins.

Monte Carlo Simulation

For advanced scenario planning, run thousands of simulations with random variations in key inputs to understand the probability distribution of outcomes.

How It Works:
  1. Define probability distributions for uncertain variables (e.g., conversion rate might be 2-4% with 3% most likely)
  2. Run 1,000+ simulations with random draws from each distribution
  3. Analyze the distribution of results to understand likelihood of different outcomes
  4. Identify the probability of hitting key milestones or running out of cash

When to use: Complex decisions with many uncertain variables, or when you need to communicate probabilities to board/investors. Most startups can skip this and focus on the three-scenario approach.

Risk Management

Use scenario planning to develop contingency plans:

Build a Risk Mitigation Plan

Define Trigger Points

Set specific metrics that indicate you're tracking to a downside scenario:

  • • "If MRR growth is <5% for 2 consecutive months..."
  • • "If CAC exceeds $500..."
  • • "If runway drops below 9 months..."
Prepare Response Actions

Document what you'll do if triggers are hit:

  • • Immediate: Cut contractor spend, freeze hiring
  • • 30 days: Reduce marketing by 30%, negotiate better terms
  • • 60 days: Workforce reduction, focus on core product
Review Regularly

Monthly review of actuals vs forecast. Are you tracking to base, upside, or downside? Update scenarios as you learn and markets evolve.

Best Practices for Scenario Planning

Be realistic: Your worst case should be plausible, not apocalyptic. Your best case should require luck but be achievable.
Vary the right things: Focus scenarios on variables you're uncertain about, not things you control completely.
Keep scenarios coherent: Variables should move together logically. If market is weak, assume higher CAC AND higher churn.
Update regularly: Scenarios aren't static. Update quarterly as you learn what's actually happening.
Share with your team: Scenarios help align everyone on risks and opportunities. Use them in planning discussions.

Model Multiple Scenarios with Ease

Formulate makes it simple to create and compare multiple scenarios to plan for any future

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