Keeping definitions stable when people change roles or leave

3 days ago
3 min read

Introduction

A funnel series survives for as long as the person counting stays in the job. When they leave, the successor receives a spreadsheet and no explanation, invents a reasonable interpretation of each column, and within a quarter the numbers describe something slightly different. Nobody notices, because the change is gradual and the columns still have the same headings.

This is the main reason small businesses cannot compare against their own history. Not that the records were lost, but that the meaning of the records changed and nothing recorded the change. Three years of data become three separate two-year fragments.

The prevention is a page of definitions and a habit of dating every alteration.

1. Keeping definitions stable when people change starts with writing them down

The foundation.

One sentence per number, stored beside the numbers rather than in a separate document. If it is not written, it does not survive a handover. This is the whole intervention in one line. A tab in the same spreadsheet is the right place.

2. Include one example each way

The disambiguation.

For every rule, an example of something that counts and something that does not. Rules are interpreted; examples are copied. This resolves most of the questions a new person would otherwise resolve alone. Take the examples from real cases that caused an argument.

3. Record who decided and when

The provenance.

A date and a name beside each definition tells the next person whether it is current and who to ask. It also makes revisiting it feel legitimate. Definitions with no author get quietly ignored. Ownership is what keeps a rule alive.

4. Make the handover explicit

The transition.

Walk the new person through the definitions before they count anything, rather than after the first month looks odd. Twenty minutes. It saves a year of incomparable data. Book it as part of the handover rather than hoping it happens.

5. Have them count a past month

The verification.

Give them a month that has already been counted and compare the answers. Any difference is a definition problem found immediately. This is the single most effective check available. Repeat it after a month as well.

6. Date every change

The essential discipline.

When a definition genuinely needs to change, write the date beside the series so every future comparison carries the warning. This makes the break manageable rather than invisible. It costs one line. Put the note in the report itself, not only in the file.

7. Restate history where you can

The repair.

If the records allow the new definition to be applied backwards, do it for as many periods as possible and say how far back it goes. Partial restatement is better than none. Label which periods are on which basis.

8. Keep the definitions short

The practical constraint.

A page nobody reads protects nothing, and five sentences is genuinely enough for five numbers. Resist turning it into a procedure manual. Length here is the enemy of survival.

9. Review them when the business changes

The scheduled maintenance.

New service, new channel, new way of taking enquiries. Each is a reason to check whether the definitions still describe reality. Annually is enough if nothing large happened.

Be careful about freezing a definition that has stopped being useful. Stability serves comparability, not accuracy, and a rule that no longer describes how the business works should be changed deliberately and dated rather than preserved out of habit.

Conclusion

Write one sentence per number and keep it beside the numbers.

Give an example on each side of every rule, record who set the definition and when, walk any new person through it before they start counting, ask them to recount a past month and compare, date every change so comparisons across it carry a warning, restate earlier periods where the records allow, keep the whole thing to a page, and review it whenever the business changes shape.