Scenario Manager (Base / Bull / Bear)

When to use

Use when a model needs to switch cleanly between Base, Bull, and Bear cases driven by a small set of assumptions, and you want every case visible and auditable on one sheet. This skill BUILDS a downloadable .xlsx from scratch in the Claude app (openpyxl plus data validation), with a live selector, formula-driven assumption pulls, a comparison table, and a recalc-and-verify pass. It is not the Claude for Excel add-in.

What it builds

Five areas: a Cover tab (selector and summary), a Scenario Inputs tab (each driver under Base, Bull, Bear), live links INTO the model so assumptions pull the active case, an Outputs comparison tab (key results across all three cases side by side), and a Checks tab.

Build workflow

1. List the drivers that differ across cases (for example growth, price, churn, capex) and find each driver's assumption cell in the model.
2. Build the Scenario Inputs block holding Base, Bull, Bear values for every driver.
3. Build a single selector cell (1, 2, or 3) with a data-validation dropdown.
4. Rewrite each model assumption cell to pull the active case via CHOOSE or INDEX referencing the selector.
5. Build the Outputs tab comparing key results across all three cases (parallel calc, see spec) so all cases show at once regardless of selector.
6. Add the Checks tab.
7. Recalculate the workbook in a real engine (headless LibreOffice).
8. Verify zero formula errors (#REF!, #DIV/0!, #VALUE!, #NAME?), confirm checks pass, then deliver the .xlsx.

Tab-by-tab spec