Murphy’s Law

An engineering adage used as a prompt to anticipate plausible failures and design proportionate prevention or recovery. It should not be read as a literal universal probability law.

Murphy's law is a memorable engineering adage about anticipating ways a system can fail. Taken literally, the claim that every possible failure will occur is false: probability, exposure, dependencies, and prevention matter. Its useful interpretation is to look for plausible errors and make important ones harder to create or easier to detect and recover from.

Translate the adage into a bounded design review. Identify what a user could reasonably misunderstand, what a component could fail to do, and how the system responds. Prioritize consequences and likelihood rather than listing every imaginable catastrophe. Redundancy can help, but duplicated components can share the same failure mode.

When to use it

When reviewing a design, preparing for a consequential task, or checking a recovery arrangement.

How it can help

Encourages checking foreseeable mistakes, shared dependencies, and whether protective measures actually work.