business-impact-modellisted

# Business Impact Model ## What this does Produces a client-ready, multi-sheet Excel workbook that turns a set of assumptions into a Year-1 revenue projection, an investment plan, and an ROI/KPI dashboard — with **live cross-sheet formulas** so every number recalculates when an input changes. It runs three scenarios side by side (Conservative / Base / Optimistic) from a single assumptions block. ## When to use it - Building the financial half of a growth strategy or proposal. - A stakeholder needs a "what if we change this input" model, not a snapshot. - You need ROI, payback, and a KPI dashboard derived from revenue pillars. - You want consistent, auditable spreadsheet conventions across deliverables. ## How to use it 1. Read [`references/model-structure.md`](references/model-structure.md) to understand every sheet, its columns, and the color/formula conventions. 2. Generate the starter workbook (deterministic — always prefer the script over hand-building cells): ```bash python scripts/build_model.py # -> business_impact_model.xlsx python scripts/build_model.py /path/to/output.xlsx # custom output path ``` The script requires `openpyxl` (`pip install openpyxl`); it exits with a clear message if missing. No network access. 3. Open the workbook and replace the **blue** placeholder inputs on `Assumptions & Inputs` with the client's real numbers across the three scenario columns. All **black** and **green** cells are f