PL-2(1): Concept of Operations

Compliance teams usually treat planning controls as “paperwork.” PL-2(1) becomes low-value only when it’s written as generic prose that nobody uses. Treated correctly, the pl-2(1): concept of operations requirement is a forcing function: you define how the system is supposed to run, who uses it, what it depends on, and what “normal” looks like. That gives assessors a clear baseline for testing security controls, and it gives operators a shared reference during incidents, change management, and onboarding.

This requirement commonly lands with the CISO or system security engineer, but the CCO/GRC lead has to make it executable: set standards for what “good” looks like, ensure ownership, ensure approval, and make sure the CONOPS aligns to the authorization boundary and the system security plan (SSP). If you’re supporting federal systems or contractor systems handling federal data, PL-2(1) is also an assessment-readiness issue. Gaps show up fast during audits because assessors use the CONOPS to understand scope, interfaces, and operational assumptions.

Regulatory text

Excerpt (provided): “NIST SP 800-53 control PL-2.1.” ¹
Framework context: PL-2 is the System Security Plan family; “(1) Concept of Operations” is an enhancement that expects a documented CONOPS as part of how the system is described and governed under the SSP lifecycle ².

What the operator must do: produce and maintain a Concept of Operations that explains how the system is used and operated, and keep it aligned with the SSP and the actual environment. The practical test is simple: if an assessor, incident commander, or new system owner reads the CONOPS, can they accurately understand how the system functions, where it connects, and which operating modes matter for security?

Plain-English interpretation (what PL-2(1) is really asking)

A CONOPS is the “how it works in the real world” document. It translates architecture and security documentation into operational reality:

• Mission and outcomes: what the system exists to do and what would constitute mission failure.
• Users and roles: who uses it (admins, end users, external parties), and what they do.
• Operational states: normal operations, maintenance, degraded mode, emergency operations, and shutdown.
• Dependencies and interfaces: upstream/downstream systems, third-party services, data feeds, identity providers, and networks.
• Boundary assumptions: what is inside the authorization boundary versus external dependencies.
• Operational constraints: hosting model, locations, uptime expectations (qualitative), staffing coverage, and support model.
• Security-relevant operational details: where authentication happens, how privileged access is performed, how data moves, and what “break-glass” looks like.

If your SSP describes controls but the CONOPS doesn’t describe the operating reality those controls support, you will struggle to show control applicability and effective implementation.

Who it applies to

PL-2(1) is relevant anywhere you are implementing NIST SP 800-53 Rev. 5 as a governing control set, including:

• Federal information systems undergoing authorization or continuous monitoring activities ².
• Contractor systems handling federal data where NIST 800-53 controls are contractually flowed down or used for assessment baselines ².

Operationally, it applies to:

• New systems entering an ATO path (or equivalent internal authorization).
• Major system changes (boundary shifts, re-platforming, new identity, new third party dependencies).
• Systems with frequent incident response or operational handoffs (SOC, NOC, SRE rotations).

What you actually need to do (step-by-step)

Use this sequence to get from “requirement” to assessment-ready operations.

1) Assign ownership and decision rights

• Control owner: name a single accountable owner (often system owner or security engineer) with authority to get inputs from architecture, operations, and product.
• Approver: define who approves the CONOPS (system owner + authorizing official delegate, or your internal governance equivalent).
• RACI: document who contributes: IAM, network, platform, third-party management, incident response.

Practical tip: the CONOPS fails when it’s written only by GRC. GRC should orchestrate; operators must author the “how it runs” content.

2) Standardize a CONOPS template that assessors can navigate

Build a template and enforce it across systems. Minimum sections that reduce audit friction:

• System purpose and mission mapping
• System boundary summary (in plain terms) and hosting model
• User populations and roles (including administrators)
• Data types handled (high-level) and where data originates/exits
• Operational states and triggers (maintenance windows, failover, emergency access)
• External interfaces and dependencies (including third parties)
• Operational support model (who monitors, who responds, escalation path)
• Security-relevant operational procedures (references to runbooks, not full duplication)
• Assumptions and constraints (what must be true for the system to operate safely)

Tie the template to your SSP structure so cross-references are easy.

3) Build the CONOPS from real operating workflows

Run a working session with:

• system owner/product owner,
• platform/infra lead,
• IAM lead,
• network/security engineering,
• incident response.

Capture facts that affect security testing and scoping:

• Where identity is sourced and enforced (IdP, PAM, break-glass)
• Where logs are generated and collected
• How secrets are stored and rotated (reference to your process)
• How changes are deployed (CI/CD, approvals, rollback)
• What “degraded mode” means (partial functionality, read-only mode, manual fallback)

4) Map CONOPS to SSP, boundary, and dependencies

Create a simple crosswalk table:

CONOPS element	Where reflected	Why it matters in audits
External interfaces	SSP boundary + interface inventory	Scoping, inherited controls, third-party reliance
Operational states	IR plan / DR plan references	Tests for contingency and incident readiness
Admin workflows	IAM/PAM procedures	Privileged access control applicability
Data flows	Data flow diagrams / inventory	Control selection and evidence expectations

This is where PL-2(1) stops being “a document” and becomes an operational reference set.

5) Approve, publish, and make it discoverable

• Store the approved CONOPS in the same controlled repository as the SSP.
• Apply document control: version, date, approver, and change summary.
• Ensure it’s accessible to assessors and to operations during incidents (with appropriate access controls).

6) Operate it: bake CONOPS updates into change management

Define update triggers:

• boundary changes,
• new external connection or third party dependency,
• major authn/authz changes,
• platform migration,
• major incident that reveals a mismatch between “described ops” and “real ops.”

Make the update measurable: tie it to your change ticket workflow and architecture review gates.

7) Establish recurring evidence

You need to prove ongoing maintenance, not just initial creation. A light-weight cadence works if it is consistent and evidenced.

Where Daydream fits naturally: Daydream can track the PL-2(1) control owner, link the CONOPS artifact to the system record, and schedule recurring evidence requests so you don’t scramble at assessment time.

Required evidence and artifacts to retain

Keep evidence that shows both existence and operational maintenance:

• Approved CONOPS document (version-controlled)
• Approval record (signed page, workflow approval, or GRC tool attestation)
• SSP cross-reference (SSP section links or a mapping table)
• System boundary and interface inventory references
• Change log showing updates tied to major changes
• Meeting notes or working session records used to develop/update CONOPS
• Evidence of periodic review (review ticket, review minutes, or attestation)

Common exam/audit questions and hangups

Assessors often probe PL-2(1) with practical scope questions:

• “Show me how the system operates in normal and degraded modes.”
• “Who are the user groups and what are their privileges?”
• “Where are the system boundaries and external interfaces defined?”
• “What third parties does the system depend on, and what happens if they fail?”
• “When was the CONOPS last updated after a major change?”

Common hangups:

• CONOPS contradicts architecture diagrams or SSP scope.
• Dependencies are missing (especially SaaS, IdP, logging pipelines, managed services).
• Operational states are vague (“high availability” stated without describing failover reality).

Frequent implementation mistakes (and how to avoid them)

1. Writing a generic CONOPS that could fit any system
   Fix: require system-specific interfaces, user roles, and operational states. If the document has no named dependencies, it will not hold up.

2. Confusing CONOPS with an architecture diagram pack
   Fix: include diagrams as appendices, but keep the main narrative focused on “who does what, when, and how the system behaves.”

3. No linkage to change management
   Fix: add an explicit “CONOPS update required” checkbox in architecture review and major change templates.

4. Omitting third-party operational realities
   Fix: list third-party dependencies and failure modes (auth provider outage, logging service outage, hosted platform incident) and the system’s fallback behavior.

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this requirement, so you should treat PL-2(1) primarily as an assessment and authorization readiness control rather than an enforcement-driven control in this context.

Risk-wise, weak PL-2(1) increases:

• Scope disputes during audits (what is in/out of boundary).
• Control misalignment (you test controls that don’t match operations).
• Incident friction (teams waste time reconciling “documented system” vs “real system”).

A practical execution plan (30/60/90)

Use phases rather than day-count precision; your actual timeline depends on system count, complexity, and documentation maturity.

First 30 days (Immediate)

• Assign PL-2(1) owners for each in-scope system.
• Publish a CONOPS template and acceptance criteria.
• Triage systems: pick the highest-risk/highest-visibility systems first.
• Draft CONOPS for one pilot system and run it through approval.

Next 60 days (Near-term)

• Complete CONOPS for remaining priority systems.
• Create SSP crosswalks and validate boundary/interface alignment.
• Add CONOPS updates as a required step in major change governance.
• Centralize evidence collection (repository + tracking in your GRC workflow or Daydream).

Next 90 days (Operationalize)

• Run the first periodic review cycle and capture attestations.
• Test CONOPS usefulness: run a tabletop or incident walkthrough using the CONOPS as the starting reference.
• Normalize metrics qualitatively: track which systems have current approvals and which have update triggers pending.

Frequently Asked Questions

What is the difference between a CONOPS and the SSP?

The SSP describes the security controls and how they are implemented. The CONOPS explains how the system operates day-to-day, including users, operating states, and dependencies, and it should point back to SSP sections where security details live.

Do we need a separate CONOPS per system, or can we have one for a platform?

Write a CONOPS per authorization boundary. If you run a shared platform, you can maintain a platform CONOPS plus system-specific addenda that document unique interfaces, user groups, and operating modes.

How detailed should third-party dependencies be?

List dependencies that affect boundary, identity, availability, logging, data exchange, or incident response. For each, document what the system does when the third party is degraded or unavailable.

What evidence is most commonly missing in audits?

Approval and maintenance evidence. Teams often have a document draft but cannot show who approved it, when it was last reviewed, and what triggered updates after changes.

Can we point to runbooks instead of documenting operations in the CONOPS?

Yes, but only if the CONOPS clearly summarizes the operational model and links to the authoritative runbooks. Assessors need a readable overview without opening ten separate operational documents.

Who should approve the CONOPS?

The system owner should approve it, with security governance sign-off per your internal authorization process. The approver needs accountability for operational accuracy and boundary correctness.

Footnotes

1. NIST SP 800-53 Rev. 5 OSCAL JSON

2. NIST SP 800-53 Rev. 5