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 to

understand every sheet, its columns, and the color/formula conventions.

1. Generate the starter workbook (deterministic — always prefer the script over

hand-building cells):

   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.

1. 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 formulas and update automatically — do not overwrite them.

1. Add or rename pillar/revenue-stream build sheets to match the engagement

(one sheet per pillar). Mirror the existing formula pattern so the Y1 Revenue Projection, Investment Plan, and ROI & KPI Dashboard roll-ups keep referencing them.

1. Sanity-check: every result cell should change when you edit a blue input,

and the workbook should open with zero #REF!/#DIV/0! errors.

Inputs

• The revenue pillars / streams for the engagement (1+).
• Per-scenario assumptions (price points, volumes, ramp curves, conversion,

spend) for Conservative / Base / Optimistic.

• Investment line items (retainer + project costs + tooling).

Output

business_impact_model.xlsx (default in the working directory, or the path you pass) — a workbook with these sheets: Cover & Summary, Assumptions & Inputs, one or more Pillar build sheets, Y1 Revenue Projection, Investment Plan, ROI & KPI Dashboard.

Notes & constraints

• Formulas are real Excel formulas (e.g. =Assumptions!C7*'Pillar 1'!N8),

never hard-coded results — this is the whole point of the model.

• Color convention (kept identical everywhere): blue font = manual input,

black font = in-sheet formula, green font = cross-sheet link, yellow fill = key result.

• openpyxl writes formulas but does not evaluate them; open the file in

Excel / Google Sheets / LibreOffice once to compute values.

• Keep state in a single assumptions block so scenarios stay consistent; never

duplicate an input across sheets — link to it.

• Use forward-slash paths. Don't assume openpyxl is installed elsewhere.