Single point of failure
The failure pattern in which only one person at a facility holds the knowledge or contacts a given function depends on, so the whole function fails the moment that one person is unavailable; the incident command chart's named backups exist specifically to eliminate this pattern.
Defined in 5 GAGE programs, which carry 18 distinct definitions of it. The wording above is taught in Senior AI Scam Defense.
How each discipline defines it
The same term does different work depending on who is using it. These are the definitions as each program teaches them, unedited.
A component whose failure alone is sufficient to cause a system-level failure, with no redundant path to prevent it. Identifying single points of failure in a safety-critical function is a core reason genuine, justified redundancy is added; the DC-10 cargo door's reliance on a single latch mechanism that could falsely indicate "locked" is a documented example of an unaddressed single point of failure in a safety-critical system. (see Topic 3.4 for the full fault-tree method used to systematically find single points of failure.)
A design weakness, named in Section 3J and Section 6, in which a protective process depends entirely on one specific person's availability, so that the process stops functioning reliably whenever that person is absent; addressed in this topic through cross training a second deliverer.
A component whose failure disables the whole system that depends on it. The token-issuing service in a control plane is one, since every agent's short-lived tokens depend on it staying available; this is named explicitly as part of the negative case for centralizing the plane.
The one page in a file that, if proven false, collapses the whole file, usually the necessity case or the data provenance file, since every other claim rests on the system being lawful to run.
The solo-business risk that every workflow depends on one person; mitigated by an honest absence fallback that covers the operator gracefully rather than impersonating them.
Where it is taught
The exact lessons this term appears in. The first 7 topics of every program are free with a free account.
- Solo Entrepreneur AI Workflows · Bonus: SMB AI Adoption Path, AI Literacy & Professional Conduct
- The Off Switch · Bounding by Design, Agentic AI Governance: Applied Mastery
- The Enterprise Control Plane · Rollout, Monitoring, and Incident Response, Agentic AI Governance: Applied Mastery
- Your conformity file under attack: the red team finds what you missed · Adversarial Governance, AI Governance: Applied Mastery
- Your Escalation Policy, Adapted From What Banks Already Do · CSFDP: Facility Protocols and Incident Command, Senior AI Scam Defense
- Resident Education at Intake, Not at the Annual Talk · CSFDP: Facility Protocols and Incident Command, Senior AI Scam Defense
- Running the first 24 hours as a facility, not as an individual · CSFDP: Facility Protocols and Incident Command, Senior AI Scam Defense
Terms it appears with
Not an alphabetical neighbourhood: these are the terms taught in the same lessons, ranked by how often they appear together.