Why we are called this
Occam's razor
A fourteenth-century principle that is still the best diagnostic tool we know for walking into a factory.
Entia non sunt multiplicanda praeter necessitatemWhat it says, and what it does not
William of Ockham was an English Franciscan friar of the fourteenth century. The phrase that bears his name does not appear in his writings in that form: the Latin wording was fixed later by commentators summarising the criterion he used, over and over, to take arguments apart.
Popular reading
The simplest explanation is the correct one.
What it says
Do not add parts that are not needed to explain what you are looking at.
A factory multiplies entities without noticing
Nobody decides on a Monday that the plant will have twelve data sources: they accumulate. A spreadsheet built to get through a bad week is still there six years later, a module covers a gap in the ERP, a paper log outlives three line managers.
None of those decisions was bad on its own, but every part has to be fed, and feeding it means typing the same figure a second time. In the end half the back office reconciles copies of the same truth and month-end closing lands on the 18th. Entities multiplied beyond necessity: here they do not cost you a logical error, they cost hours and money.
Applying the razor is not cost-cutting
When a company asks us to "simplify", the first thing we do is touch nothing for two weeks: we audit. Without that picture you cannot cut, because you do not know what is doing work. Then the question gets applied part by part.
Is this part doing any work?
However elegant it is. A process that existed only to reconcile two systems disappears once one of the two is no longer needed.
However complex it is. Signed batch traceability in a pharmaceutical plant is not a superfluous entity: it is the job.
Where the razor gets it wrong
This is worth saying, because almost nobody who uses it as a sales pitch admits it: it is a heuristic, not a law. It guides the search, it does not guarantee the answer. Some complexity is irreducible, and some simple explanations are simply false.
On a shop floor the expensive mistake has a recognisable shape: you remove the control that looked redundant and find out three months later that it was the only thing catching one failure on line 2. That is why the method starts by measuring, and why the removal plan is reviewed with the people who operate the machine. Ockham gave a rule for choosing between explanations that are equally good; if you have not measured, you do not know whether they are.
The symbol
That is where the brand comes from: the O of Occam opened by a clean 45° cut. No scissors, no drawn razor, just the result of the cut. The name has lived in two spellings since medieval Latin — Occam in English, Ockham in Spanish — and we use the first. The idea is the same in both.