PM-5: System Inventory

PM-5 requires you to develop and keep current a complete inventory of organizational systems, with clear ownership and an update mechanism tied to real operational change. To operationalize it fast, define what “system” means for your scope, centralize the authoritative inventory, connect it to onboarding/offboarding workflows, and retain repeatable evidence of updates and reviews. ¹

Key takeaways:

• Treat the system inventory as an authoritative record with an owner, a process, and recurring evidence, not a one-time spreadsheet.
• Scope decisions drive audit outcomes; document what counts as a “system” and what is explicitly out of scope.
• Connect updates to change events (new system, major change, decommissioning) so the inventory stays current between formal reviews.

The pm-5: system inventory requirement is straightforward on paper and painful in practice: auditors expect you to prove you know what systems you operate, which ones handle sensitive data, and who is accountable for them. A “system inventory” that lives in a static file, updated ad hoc, usually fails the operational reality test because it can’t keep pace with cloud adoption, SaaS sprawl, acquisitions, shadow IT, and third-party managed environments.

PM-5 sits in the NIST SP 800-53 Program Management family, so examiners often read it as an organizational capability. They will look for governance (ownership, defined scope, defined update triggers) and operational execution (timely updates, decommissioning discipline, alignment to ATO/FedRAMP boundary concepts where applicable). The goal is not asset-level discovery; it’s a system-level view you can use to drive risk decisions, map controls, and support authorizations.

This page gives you requirement-level implementation guidance you can put into motion quickly: what to include, who needs to be involved, how to run the workflow, and what artifacts you must retain to survive an assessment with minimal rework. ²

Regulatory text

Requirement (PM-5): “Develop and update [organization-defined parameter] an inventory of organizational systems.” ¹

Operator interpretation (what you must do):

1. Develop an inventory: create a defined record of the systems your organization operates or is responsible for within scope.
2. Update the inventory: keep it current through a repeatable process, not informal memory or periodic scramble.
3. Define the parameter: NIST leaves specifics to you (the organization-defined parameter). Your job is to set and document what “inventory” contains, how often it is reviewed, and what events trigger updates. ¹

Plain-English interpretation of the requirement

You need a living list of your systems that a reasonable reviewer can rely on to answer: “What systems exist, who owns them, and what’s their status?” If you cannot produce an accurate inventory, you will struggle to scope security controls, identify system interconnections, manage risk, or respond to incidents.

A PM-5 inventory is typically system-level, not a full hardware/software asset inventory. Your inventory should still be able to link to deeper technical inventories (CMDB, cloud accounts, endpoint tools), but PM-5 is satisfied when you can show an authoritative, maintained catalog of systems with enough metadata to manage governance.

Who it applies to

Entities:

• Federal information systems
• Contractors operating systems that handle federal data (for example, as part of a contract boundary or inherited environment) ¹

Operational contexts where PM-5 becomes exam-critical:

• You operate multiple environments (on-prem, cloud, SaaS) with unclear ownership.
• You have separate inventories across IT, security, and procurement that disagree.
• You rely on third parties to host or operate systems, but you remain accountable for the system boundary and risk decisions.

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

Step 1: Set scope and definitions (write them down)

Decide and document:

• What counts as a “system” in your organization (examples: a business application, a platform service, a data pipeline, a cloud landing zone, a shared identity tenant).
• What does not count (examples: individual laptops, single containers, ephemeral build jobs), and where those are tracked instead.
• System boundary logic: when a component is part of an existing system vs. a new system record.
• System inventory fields you will require (see Step 3).

Deliverable: a short “System Inventory Standard” or procedure that defines these rules and names the authoritative source.

Step 2: Assign ownership and governance

PM-5 fails most often because nobody “owns” the inventory end-to-end.

Minimum governance roles:

• Control owner: accountable for PM-5 design and evidence.
• System owner: accountable for correctness of each system record.
• Custodian/admin contact: day-to-day technical contact.
• Inventory administrator: manages the tooling, QA checks, and reporting cadence.

Practical rule: no owner, no system entry. If a system cannot have an owner, treat it as a risk item and escalate.

Step 3: Build the minimum viable inventory schema

Your schema must support governance and scoping decisions. A workable baseline:

• System name (unique), system identifier
• Business purpose / mission function
• System owner (name/role), technical contact
• Environment type (on-prem, cloud, SaaS, PaaS)
• Data types processed/stored and sensitivity indicator (your classification)
• Authorization or assessment status (if applicable to your program)
• Operational status (planned, active, deprecated, decommissioned)
• External dependencies and key third parties (hosting provider, managed service operator)
• Primary repositories of truth (CMDB record, cloud account/subscription IDs, ticketing project, IaC repo)
• Last review date, last update date, change ticket references for major updates

Keep it tight. Every field you add becomes an evidence obligation.

Step 4: Reconcile sources and establish the authoritative record

Most organizations already have partial inventories:

• IT CMDB
• Cloud account/subscription lists
• SaaS lists from SSO/IdP, finance, procurement
• Vulnerability scanner targets
• Network segments and DNS zones

Your job is to reconcile and declare one authoritative “system inventory” record. Other inventories can feed it, but they cannot replace it if they don’t meet your schema and governance needs.

A practical approach:

• Import existing sources into a working dataset.
• De-duplicate by system boundary rules.
• Resolve ownership gaps via business unit leaders.
• Tag systems that handle federal data or are in-scope for specific compliance boundaries.

Step 5: Operationalize updates through workflows (the part auditors care about)

Define update triggers and make them hard to bypass:

• New system intake (architecture review, security review, procurement intake)
• Material system change (new data type, new hosting model, new major integration)
• Decommissioning (shutdown approval, data retention/transfer confirmation)
• Third-party change that affects your boundary (provider migration, service model change)

Implementation pattern that works:

• Add a mandatory “System Inventory Update” task to change tickets and project templates.
• Require system inventory record creation before production go-live.
• Require inventory update before ATO package updates (if applicable).
• Run periodic QA checks (for example: compare SSO app catalog to system inventory entries and investigate gaps).

Step 6: Review cadence and quality checks

NIST does not prescribe a specific frequency in the excerpt; you must define it as part of the organization-defined parameter and then follow it. ¹

Quality checks to institutionalize:

• Orphan systems (no owner)
• Stale reviews (past due per your defined rule)
• Systems marked active without environment identifiers or dependency mapping
• Systems with federal data indicators but missing compliance boundary metadata (if your program requires it)

Step 7: Map PM-5 to recurring evidence artifacts (make it assessment-ready)

Recommended control practice: map PM-5 to a control owner, a written procedure, and recurring evidence artifacts so you can prove the control operates. ¹

If you use Daydream, treat PM-5 as a requirement with:

• A named control owner
• A documented operating procedure
• Scheduled evidence requests (exports, tickets, review attestations)
• A single place to show auditors what changed and when, without rebuilding the story each exam cycle

Required evidence and artifacts to retain

Keep evidence that shows existence, currency, and operation:

Core artifacts

• System Inventory Standard/procedure (scope, definitions, fields, update triggers)
• Current system inventory export (with required fields populated)
• Role/ownership mapping (who owns PM-5; who owns each system)

Operational evidence

• Samples of tickets showing inventory updates tied to real changes (new system, major change, decommission)
• Review/attestation records (meeting notes, sign-offs, workflow approvals)
• Exception log for systems that cannot meet requirements (with risk acceptance and target remediation)

Quality evidence

• Periodic reconciliation reports (SSO/procurement/CMDB vs. system inventory) and follow-up actions
• Metrics dashboard screenshots are fine if they tie back to system records and actions; avoid vanity metrics without traceability

Common exam/audit questions and hangups

Expect questions like:

• “Define ‘system’ for your organization. Show me the written definition.”
• “Which inventory is authoritative? Why?”
• “Show evidence you update the inventory when systems change.”
• “How do you know this inventory is complete?”
• “Who owns System X? Who approved its go-live?”
• “Show decommissioning records for a system removed from the inventory.”

Hangups that trigger findings:

• Multiple conflicting inventories with no reconciliation story
• Inventory has names but lacks owners, status, or boundary context
• Updates happen only right before audits, with no operational trail

Frequent implementation mistakes and how to avoid them

Mistake	Why it fails	Fix
Treating PM-5 as an asset inventory	Auditors need system governance, not device counts	Keep PM-5 system-level; link to asset tools as supporting evidence
No system boundary rules	Teams disagree on what a “system” is	Write boundary criteria and apply them consistently
Inventory ownership is informal	Nobody is accountable for correctness	Assign system owners and enforce “no owner, no entry”
Manual updates with no triggers	Inventory drifts immediately	Embed updates into change/project workflows
No evidence trail	You can’t prove operation	Retain ticket samples, approvals, and review records

Enforcement context and risk implications

No public enforcement cases were provided in the source material for PM-5. In practice, PM-5 gaps usually surface as assessment findings because incomplete system inventories cascade into other control failures: incomplete scoping, missed vulnerability coverage, undocumented interconnections, and unclear responsibility during incidents. Treat PM-5 as a foundational governance control that reduces the likelihood of control “blind spots.” ²

Practical 30/60/90-day execution plan

First 30 days: Establish the rulebook and baseline

• Name the PM-5 control owner and inventory administrator.
• Publish the “system” definition, boundary rules, and required fields.
• Identify existing data sources (CMDB, cloud org structure, SSO, procurement).
• Create a baseline inventory draft and resolve duplicate records.
• Assign owners for the highest-risk systems first (systems handling federal data, identity, network, logging).

Days 31–60: Make updates operational

• Embed inventory updates into change management and project intake workflows.
• Create a decommissioning checklist that includes inventory status change and data handling confirmation.
• Start reconciliation checks (SSO/procurement vs. inventory) and track gaps as tickets.
• Run the first formal inventory review meeting and record decisions.

Days 61–90: Prove durability and audit readiness

• Produce an evidence pack: procedure, current export, sample tickets, review sign-offs, exception log.
• Test a mock audit: pick a system at random and trace ownership, data types, dependencies, and last change.
• Tighten fields that are consistently incomplete; remove nonessential fields that nobody can maintain.
• Automate reminders and evidence capture where possible (for example, scheduled exports and review tasks in Daydream).

Frequently Asked Questions

What is the difference between a system inventory and a CMDB?

A CMDB often tracks configuration items and relationships at a granular level, while PM-5 expects an authoritative inventory of organizational systems with governance metadata like ownership, status, and scope. You can feed PM-5 from a CMDB if the CMDB contains the required fields and you can show an update process. ¹

Do SaaS applications count as “organizational systems”?

They often do if they process organizational data or support mission/business functions. Define your rule in writing, then apply it consistently across procurement intake and SSO catalogs. ¹

How do we handle systems run by third parties?

Include the system in your inventory if you are accountable for its use, boundary, or risk decisions, and record the third party dependency and operational model. Keep contracts and responsibility assignments linked as supporting artifacts.

How current does the inventory need to be?

PM-5 requires you to define and follow an update expectation as part of your organization-defined parameter. Set update triggers tied to change events and back them with ticket evidence so you can show the inventory stays current between reviews. ¹

What’s the minimum evidence an auditor will accept?

A written procedure defining scope and updates, a current inventory export, named owners, and samples showing updates tied to real system lifecycle events. Add reconciliation or review records to show you check completeness and accuracy over time.

We have multiple inventories that don’t match. What should be the “source of truth”?

Pick one authoritative system inventory for PM-5, then document how other sources feed it and how conflicts are resolved. Auditors accept multiple sources if you can show a controlled reconciliation process and consistent outcomes.

Footnotes

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

2. NIST SP 800-53 Rev. 5