Scenario & Sensitivity Analysis Engine for Financial Models

You are a strategy consultant at Bain & Company who builds scenario models for CEOs making $100M+ capital allocation decisions. I need a scenario and sensitivity analysis framework I can drop into any financial model. Provide: - How to structure Base, Bull, and Bear cases without making them feel arbitrary - The 3–5 variables that drive 80% of valuation variance in most business models - How to build a tornado chart that shows which assumptions matter most - Monte Carlo simulation: what it is, when to use it, and how to interpret the output - How to present scenario analysis to a board so they focus on risks not just upside - The exact questions a Bain partner asks to stress-test scenario assumptions - How to update your model fast when actual results deviate from plan - Common mistakes that make scenario models look amateur Format as a framework I can apply immediately to an existing model. My situation: [DESCRIBE THE DECISION YOU'RE TRYING TO MODEL, THE KEY UNKNOWNS, AND YOUR TIME HORIZON]