Criticality Analysis
LOW ✓ MODERATE ✓ HIGHRequirements NIST SOURCE
Identify critical system components and functions by performing a criticality analysis for [systems, system components, or system services] at [decision points in the system development life cycle].
Discussion (NIST Supplemental Guidance)
Not all system components, functions, or services necessarily require significant protections. For example, criticality analysis is a key tenet of supply chain risk management and informs the prioritization of protection activities. The identification of critical system components and functions considers applicable laws, executive orders, regulations, directives, policies, standards, system functionality requirements, system and component interfaces, and system and component dependencies. Systems engineers conduct a functional decomposition of a system to identify mission-critical functions and components. The functional decomposition includes the identification of organizational missions supported by the system, decomposition into the specific functions to perform those missions, and traceability to the hardware, software, and firmware components that implement those functions, including when the functions are shared by many components within and external to the system. The operational environment of a system or a system component may impact the criticality, including the connections to and dependencies on cyber-physical systems, devices, system-of-systems, and outsourced IT services. System components that allow unmediated access to critical system components or functions are considered critical due to the inherent vulnerabilities that such components create. Component and function criticality are assessed in terms of the impact of a component or function failure on the organizational missions that are supported by the system that contains the components and functions. Criticality analysis is performed when an architecture or design is being developed, modified, or upgraded. If such analysis is performed early in the system development life cycle, organizations may be able to modify the system design to reduce the critical nature of these components and functions, such as by adding redundancy or alternate paths into the system design. Criticality analysis can also influence the protection measures required by development contractors. In addition to criticality analysis for systems, system components, and system services, criticality analysis of information is an important consideration. Such analysis is conducted as part of security categorization in RA-2.
Implementation Guidance
Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.
No engineering interpretation has been authored for RA-9 yet. This section is architected to receive it — see the Requirements and Assessment sections above for the authoritative NIST source content in the meantime.
Assessment
Assessment Objectives
- systems, system components, or system services to be analyzed for criticality are defined;
- decision points in the system development life cycle when a criticality analysis is to be performed are defined;
- critical system components and functions are identified by performing a criticality analysis for <RA-09_ODP[01] systems, system components, or system services> at <RA-09_ODP[02] decision points in the system development life cycle>.
Examine
[SELECT FROM: Risk assessment policy; assessment reports; criticality analysis/finalized criticality for each component/subcomponent; audit records/event logs; analysis reports; system security plan; other relevant documents or records].
Interview
[SELECT FROM: Organizational personnel with assessment and auditing responsibilities; organizational personnel with criticality analysis responsibilities; system/network administrators; organizational personnel with security responsibilities].
Test
[SELECT FROM: Organizational processes for assessments and audits; mechanisms/tools supporting and/or implementing assessments and auditing].
Overlays
STIGs & CCIs
No STIG checks or CCI mappings are currently loaded for RA-9. This section is architected to display, per product: STIG ID, Finding ID, Severity, Title, Description, Check, Fix, CCI, and NIST control mapping — but nothing is populated here until a real DISA STIG/CCI dataset is ingested.
Learn more about STIG/CCI integration →Evidence
Categorized from the SP 800-53A "Examine"/"Test" artifact list above by keyword — not an authoritative NIST evidence list.
Policy
- Risk assessment policy
- system security plan
Testing
- Organizational processes for assessments and audits
- mechanisms/tools supporting and/or implementing assessments and auditing
Other Records
- assessment reports
- criticality analysis/finalized criticality for each component/subcomponent
- audit records/event logs
- analysis reports
- other relevant documents or records