Comparison
Bus factorvsSilo
Bus factor
one person was on holiday and the release could not go out until they got back.
The number of people who would have to be unavailable before work stops. It is usually one, and it is usually one for reasons nobody chose: the person who set up the pipeline, the only one with the production credential, the only one who understands the pricing rules. It is worth raising in planning rather than after the fact, because the fix — pairing, documentation, rotating who does the scary task — takes weeks and only works before the absence.
Full entry →Silo
the database changes all go through one team, and their queue is nine weeks long.
A group holding knowledge or authority that others need and cannot get. Silos form for good reasons — specialism, security, historical accident — and they turn every cross-boundary change into a scheduling problem. The question worth asking is whether the boundary is protecting something real or merely preserving a queue, because the second kind is usually dissolved by giving the other teams a supported self-service route.
Full entry →