Failure modes and what to do.
HOW AUTOMATION FAILS
Silently. That is the defining characteristic.
A person making an error notices. A system making the same error repeats it.
COMMON FAILURES
Input format changes and extraction breaks Edge cases handled wrongly Errors compounding across steps Output nobody checks
WHAT TO BUILD IN
Sampling: check a proportion regularly
Alerts when something looks unusual A clear way to stop it Logging, so you can see what happened
THE QUESTION TO ANSWER BEFORE BUILDING
How would I know if this went wrong?
WHEN IT DOES GO WRONG
Stop it Establish what was affected and over what period Correct what you can Tell anyone affected Fix the cause before restarting
THE PERIOD QUESTION
Frequently the worst part. An error running for three months affects three months of output.
REVIEWING
Automation should be reviewed periodically even when it appears to work.
THE PRINCIPLE
Automate cautiously, check regularly, and keep a person accountable.
