Any component whose failure halts the whole will eventually set the system's reliability.
The practical exercise is to enumerate what would halt operations and check how many have a genuine second path. Most organisations discover several they did not know were single.
In practice
- A hospital with backup generators, redundant water and one pharmacist trained on the compounding machine has one thing standing between it and closure.
- A firm with two suppliers, two data centres and one certifying laboratory has one single point of failure and does not know it.
- Further reading
- Wikipedia
- Subject
- Risk & Reliability
- Essay
- How accidents actually happen