Crossfooting: calculating a result in several ways and comparing the results.
It’s one way of building in an alert that something is amiss. Let’s see an example and an even better example.
We have a project involving stores, and their Lease Expiration is a critical component. The image below is a section of the workbook where we have summaries of all the data.
What’s going on? 300? 307? Obviously, there is something wrong. Thanks to crossfooting, we see it. But this isn’t good enough.
The “Beware of Evil Dogs” sign is bright yellow and has a dramatic scene because it grabs attention. Good crossfooting uses an attention-grabber so that you don’t have to remember to inspect each and every data point.
Now we have an effective attention-grabber by using an IF statement and conditional formatting. A quick glance in this area and we know if we have crap data or trustworthy data.
The red “NOT OK!” alerts us and sends us out to check our formulae and ask questions of the rest of the team. The problem: someone tried to make an update and a sloppy cut-&-paste threw everything out of line.
We’re all good now.
That’s it for today. I’ve used this technique for many years and never knew that it had a name. ‘Crossfooting.’
Not very descriptive but if it helps keep the world’s data clean, well ok.