How impact is scored
Each exhibit is scored 0 to 10 on five dimensions, using only facts from its named public source. The overall impact is the plain average of the five, to one decimal place. The home page draws it as five dots, one dot for every 2 points.
Scores sit on the levels below. An odd score means the facts fall between two levels.
The score measures how far an outage reached, not who was at fault.
Reach
Who was directly affected
| Score | Meaning |
|---|---|
| 0 | No outside users |
| 2 | Inside one organization |
| 4 | One product's users in one region |
| 6 | One product's users worldwide |
| 8 | Several major services, worldwide |
| 10 | Across industries, at the level of society |
Duration
Time until the main service was back
| Score | Meaning |
|---|---|
| 0 | Under 5 minutes |
| 2 | 5 to 30 minutes |
| 4 | 30 minutes to 2 hours |
| 6 | 2 to 8 hours |
| 8 | 8 to 48 hours |
| 10 | Over 48 hours, or never restored |
Loss
What was lost for good
| Score | Meaning |
|---|---|
| 0 | Nothing |
| 2 | A small cost that can be recovered |
| 4 | Lost revenue stated in the source, no data lost |
| 6 | Some data lost for good, or a stated loss of $10 million or more |
| 8 | A lot of data lost for good, or a stated loss of $100 million or more |
| 10 | The whole asset lost: vehicle destroyed, mission failed |
Recovery
How hard it was to recover
| Score | Meaning |
|---|---|
| 0 | Recovered on its own |
| 2 | One-click rollback or config revert |
| 4 | Remote manual intervention |
| 6 | Several teams, systems rebuilt |
| 8 | On-site access, or fixing machines one by one |
| 10 | Cannot be fixed, only replaced |
Cascade
How far it spread beyond the system that failed
| Score | Meaning |
|---|---|
| 0 | No spillover |
| 2 | Only the owner's own dependent systems |
| 4 | A few customers or partners |
| 6 | Many downstream sites of one provider |
| 8 | Large parts of the internet, or several industries |
| 10 | Flights, hospitals or emergency lines halted at scale |