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A model is only finished when someone else can run it

I inherited a ten-market utilisation model that worked – as long as the person who built it was in the room. Values were typed straight into formulas, assumptions lived in people’s heads, and every update risked breaking something.

I rebuilt it with no hardcoded values: inputs in one place, logic in another, checks that flagged when the data didn’t add up. It fed Databricks and Power BI downstream.

But the real finish line was the handover. I wrote user guides and trained the department director, a technical project manager and the CFO to run it themselves.

The test I now apply to any model or report: if I disappeared tomorrow, could the business still use it and trust it? If not, it isn’t done – it’s dependent.

Question

How do we stop our models and reports depending on the one person who built them?

Terminology

Hardcoded value – a number typed straight into a formula instead of referenced from an input cell. Easy to write, hard to find, and the most common way a model quietly breaks.

Context

Many business models work – as long as the person who built them is in the room. Assumptions live in people’s heads, and every update risks breaking something.

Experience

At E.ON Drive Infrastructure I inherited a ten-market utilisation model in exactly that state, and rebuilt it.

Observations

I took out every hardcoded value: inputs in one place, logic in another, and checks that flagged when the data didn’t add up. It fed Databricks and Power BI downstream.

But the real finish line was the handover. I wrote user guides and trained the department director, a technical project manager and the CFO to run it themselves.

Research

A simple test for any model: hand it to a colleague with the user guide and walk away. If they come back with questions about how it works rather than what it says, it isn’t finished.

Focus In On: Responsible for Finance / CFO

New Areas of Value:

Compliance and data quality is right first time, on time, every time

Improved resilience and workload management across finance team

Improvements around:

Unable to produce accurate timely reports

Finance function under a lot of pressure from operational tasks

Relevant Skills

Relevant Business Perspectives

Relevant Industries

Practice Group