How should teams document and manage common controls?
The common-control provider is responsible for implementing, assessing, and monitoring the common portion. The receiving system owner confirms applicability, documents actual inheritance, implements and assesses any system-specific portion, and addresses gaps that the provider's capability does not cover.
A matching control identifier is insufficient. Compare the completed control and enhancement text, parameter values, implementation boundary, provider dependencies, assessment scope and date, findings, and current operating conditions. NIST's example treats CP-2 as hybrid when an organization supplies a common contingency-plan template and each system owner tailors it for system-specific use.
A shared capability can also create concentration risk: NIST notes that a can introduce a single point of failure. The provider's monitoring and change notices should therefore identify affected consumers, known deficiencies, and the action expected from each system owner.
- Identify the organizational entity, system, service, or environment that provides each common-control capability.
- Reference the provider's implementation description, completed parameters, assessment results, monitoring output, dependencies, and known deficiencies.
- List each consuming system and the exact control or control portion it inherits.
- For a , assign the common and system-specific implementation, assessment, monitoring, and remediation work separately.
- Reevaluate inheritance when the provider, control version, parameters, boundary, service, assessment result, or relevant threat conditions change.
Section 2.3 defines common, system-specific, and hybrid implementation approaches and warns that matching control identifiers do not establish adequate inheritance.
Section 3.2.3 explains how common controls and system-specific portions of hybrid controls are assessed and made available to inheriting systems.
Risk Management Framework guidance for identifying common controls, documenting inheritance, and maintaining common-control information.