The same information, typed in three places, by three people, who all think they are right

A customer changes his delivery address. He mentions it on a call.

The person on the call updates it in her sheet. Nobody tells accounts, so the invoice goes to the old address. The dispatch register was written last week, so the material goes to the old address too. Three weeks later somebody updates the master list, which by then disagrees with everything else.

Now you have one customer and three addresses, and the only way to find the right one is to call him again and ask.

Duplicate entry is not a time problem

Everyone treats it as one. It takes two minutes, so what is the harm.

The harm is that the moment a fact exists in two places, the two can disagree, and nothing in your business notices when they do. There is no alarm. The sheet does not go red. You find out when a delivery comes back, or when a customer is annoyed, or when two reports do not match and somebody spends an afternoon working out which is right.

And it never gets reported upwards, because to the person doing it, it is just normal work. She is not going to come and tell you she typed something twice today. She typed it twice last year too.

The rule worth holding on to

Any single fact should be entered once and then read from wherever it is needed. The address lives in one place. The rate lives in one place. The order quantity lives in one place.

That is not a technology idea. It is just a rule about who owns a fact, and software is simply the easiest way to hold the rule.

It also changes something people do not expect. Arguments go down. When there is one version, nobody has to be wrong in front of anybody.

Pick one thing today: a customer address, a rate, a stock number. Count how many places in your business it is stored. If the answer is more than one, which one is correct?

One fact, entered once, read everywhere it is needed. That is usually the first thing we fix. Tell us which fact causes the most trouble in your business.