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6.2·6 min read

Checks That Catch Errors

A few automated checks - does it balance, does cash tie - catch most modeling mistakes instantly.

By the end you can
  • Add a balance check to a model
  • List the tie-outs that validate a build
Balance check=AssetsLiabilitiesEquity=?0\text{Balance check} = \text{Assets} - \text{Liabilities} - \text{Equity} \stackrel{?}{=} 0
Put this on the model as a live row. Anything other than zero means an error.
  • Does it balance? Assets - Liabilities - Equity must equal zero every period.
  • Does cash tie? ending cash must equal the cash line.
  • Roll-forwards consistent? Each ending balance equals the next beginning balance.
  • Sanity-check margins, growth, and ratios - do the outputs look like a real business?
Make the check loud

Professionals put a balance-check row at the top of the model that turns red the instant it is non-zero. Catching the break the moment it happens is far cheaper than hunting it down later.

Check yourself

Your balance check shows Assets - Liabilities - Equity = 5. What does it mean?

Practice in the simulator

Lock it in by building it yourself in a live, graded spreadsheet.