[This tale is told with permission from the company involved. No doubt it has happened to many others.]

Every year, this company recruited graduates for roles across their business, but primarily to fill vacancies in operations teams.

A recent recruit really impressed.

Alongside their enthusiasm to get involved, it turned out they were also a whizz with Excel.

They could create macros and spreadsheet automations beyond what most of the existing employees thought possible.

They were like some sort of Excel magician.

Before they knew it, the new recruit had automated a lot of the manual, low-value work that used to take up so much of your experienced employees’ time.

Everyone was delighted. The recruit got to spend most of their time doing what they loved (Excel magic) and everyone else got to concentrate on more interesting and higher-value work.

And then the recruit left.

Everything was fine initially.

The spreadsheets continued to work but.. No-one knew how they worked and no-one dared to change anything in case it broke the magic spell.

Inevitably, something did go wrong with one of the spreadsheets. This caused some small knock-on effects that accumulated into a more significant error.

To add to the problem, the team did not spot the issue immediately. It took a query from a client a few weeks later to alert the company that something was amiss.

It took time to identify and fix the problem, to re-run and re-issue the numbers, and to compensate those affected.

The true cost of taking on this recruit was painfully high.

If you have an Excel magician in your business, make sure you plan for their disappearance.