Explain like I'm five · Emerging Tech

What is Quantitative Risk Analysis?

Quantitative risk analysis, told as a story about a safety officer who multiplies probability by impact and writes risk as one number on a scoreboard.

this booth looks kind of risky, doesn't it?'looks risky' means something different to every person

Every safety officer says something different when a booth 'looks risky.''Looks risky' means something different to every person.

this looks fine, safe enoughno, this looks very dangerouswhen the same booth gets different verdicts, you can't tell what to fix first

The same booth gets different verdicts from different officers.When the same booth gets different verdicts, you can't tell what to fix first.

×42quantitative risk analysis = probability × impact, written as one single risk numbera number instead of a feeling — so everyone ranks risks from the same figures

Quantitative risk analysis multiplies probability by impact, writing risk as one single number.A number instead of a feeling — so everyone ranks risks from the same figures.

Measure probabilityhow often might it happen
Measure impacthow big would the damage be
Multiply for a scoreprobability × impact
Rank by scorefix the highest risk number first
THE RISK FORMULArisk = probability × impactlow probability, big impact → medium riskhigh probability, big impact → high riskthe score decides the order of fixesALE (annual loss expectancy) puts risk in money terms

Risk comes from multiplying probability by impact.Formulas like ALE (annual loss expectancy) express risk as the expected loss in money over a year.

42numbers make risks easy to compare and prioritizeguess the probability wrong, and the risk score is wrong toothe risk score looks precise, but a human guess still sits underneath it

Estimate the probability wrong, and the risk score is wrong too.The risk score looks precise, but a human guess still sits underneath it.

In one breath

Quantitative risk analysis = calculating probability × impact to compare the size of risks as a single number.

Quantitative risk analysis scores a risk as probability multiplied by loss magnitude, letting different risks be compared and prioritized objectively. ALE (Annual Loss Expectancy) and ROSI (Return on Security Investment) are common tools, risk matrices serve as a semi-quantitative aid, and all are typically paired with qualitative analysis (high/medium/low judgment calls) as a complement.

When grown-ups say it

Annual Loss Expectancy
The expected loss for one year, calculated in money. Single loss (SLE) times yearly occurrence rate (ARO).
Risk Matrix
Placing a risk into one grid cell by its probability and impact. A way of showing the same idea with colored cells instead of numbers.
Qualitative Risk Analysis
Judging risk only as high, medium, or low. A complementary method that pairs with the quantitative one.
Return on Security Investment
A calculation of whether security spending pays for itself. It feeds the quantitative risk number into a spending decision.
Project Risk Management
Finding and preparing for risks to a project in advance. Here risk gets a number; that page covers a framework for managing project risk. → the umbrella you carry even on a dry day
Drone Security Threats
A real-world threat this same risk scoring applies to. These drone threats get sized up the same way. → the drone held up by an invisible string
NFT
A digital asset whose value swings wildly. Its price-swing risk can be put in numbers too. → the certificate nobody can quietly alter
4th Industrial Revolution
The big wave made when many new technologies combine. The story that frames this whole exhibit hall. → the 4th Industrial Revolution
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