Operations · Documentation
Documentation
The written record of how the environment is built, why it is built that way, and how to operate it.
FoundationalUpdated 2026-09-01
Overview
Useful IT documentation has four layers: architecture (why and how it fits together), configuration (what is set where), runbooks (how to perform and recover operations) and reference (addresses, accounts, contacts, contracts).
Documentation stays current only when it is part of the work, updated by the change that altered the system, and reviewed when someone follows it during an incident.
Security considerations
- Classify and protect documentation; it is a complete map of the estate for anyone who obtains it.
- Keep an offline copy of critical recovery documentation for scenarios where systems are unavailable.