Knowledge
What is the four-eyes principle?
“Four-eyes release” appears on several of our pages. Here it is in plain words: what the principle is, why it matters in quality management, and how an eQMS enforces it rather than merely recommending it.
In one sentence
The four-eyes principle means that an important decision — such as releasing a document — is not made by one person alone, but has to be reviewed and confirmed by a second. Four eyes catch more than two: mistakes, blind spots and conflicts of interest are more likely to surface.
Why it matters in a QMS
A quality system depends on being able to trust released documents. ISO 9001 (§7.5.2) therefore requires documented information to be reviewed and approved before release — deliberately two steps. Review is the substantive check; approval is the responsible confirmation. The four-eyes principle turns that into the rule that one person doesn't do both alone.
How an eQMS enforces it
On paper the four-eyes principle is easy to bypass. An eQMS makes it a property of the system.
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Distinct roles
Reviewer and approver are distinct roles — and the author cannot make their own document valid on their own.
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Enforced, not recommended
The system won't let a single person release at all — it stays a draft until the second approval arrives.
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Signed & attributable
Every approval is cryptographically signed — provable who reviewed and who approved, not an editable line in a list.
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Provable in an audit
The distinct, signed approvals are fixed in the evidence — without anyone keeping a log by hand.
In short
The four-eyes principle is the difference between “someone ticked it off” and “two responsible people stand behind it — provably”. An eQMS turns that into a rule you can't bypass by accident. Why easo →
Frequently asked questions about the four-eyes principle
What does the four-eyes principle mean?
That an important decision — such as releasing a document — is not made by one person alone, but has to be reviewed and confirmed by a second. Four eyes catch more than two.
Does ISO 9001 require the four-eyes principle?
Not literally. But ISO 9001 (§7.5.2) does require documents to be reviewed and approved before release — review and approval are distinct steps. The four-eyes principle is the usual, cleanest way to meet that.
What is the difference between review and approval?
Review is the substantive check by a competent person; approval is the responsible confirmation that the document applies. They are different roles — and ideally different people from the author.
Is a “reviewed” tick enough?
No. A tick anyone can set and change convinces no audit. The approval must be bound to a specific person and recorded immutably — in easo, signed.
How does easo enforce the four-eyes principle?
easo enforces distinct, signed approvals: the author cannot make a document valid alone — only a second authorised person's signed approval makes it valid, and who reviewed and who approved is on record.
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