Failure rates start high from defects, fall to a low steady rate, then rise again with wear-out.
It is why burn-in testing exists: run components hard before shipping so the early-failure population dies in the factory rather than at the customer. The same shape appears in employee tenure and in new-code defect rates.
In practice
- A fleet of new vehicles has a bad first quarter, four steady years, then a maintenance bill that arrives all at once.
- A team of new hires produces its worst month first, its best years next, and its highest turnover just as everyone becomes expensive.
- Further reading
- Wikipedia
- Subject
- Risk & Reliability
- Essay
- How accidents actually happen