| Scope and covered activity | ISO/IEC 27005 is guidance for information security risk management that supports ISO/IEC 27001 and risk-based control decisions. | ISO 31000 is broad risk-management guidance for any type of organizational risk, not only information security risk. | Write the scope memo so teams can see when ISO/IEC 27005 is the implementation structure, when ISO 31000 controls the obligation or assurance question, and where evidence can be reused without changing the source test. |
|---|
| Who must act | ISO/IEC 27005 ownership should sit with the team that can operate the relevant management system, control process, risk method, supplier relationship, incident process, privacy process, or AI governance scope. | ISO 31000 ownership should follow that source's role model, such as regulator-facing accountable body, service organization, framework owner, provider, customer, processor, deployer, supplier, or risk owner. | Do not copy owners from one side to the other; map accountable owners, reviewers, and approvers separately. |
|---|
| Trigger or threshold | ISO/IEC 27005 work is triggered by scope definition, implementation, certification readiness, customer assurance, control gaps, incidents, supplier changes, or management review. | ISO 31000 work is triggered by its own legal, assurance, framework, contract, customer, or risk-management event. | Route intake using this trigger for standards implementation, regulatory response, assurance report, framework mapping, customer request, or operational remediation. |
|---|
| Core obligations | ISO/IEC 27005 requires practical governance: scope, roles, risk or impact decisions, evidence, operating cadence, monitoring, review, and improvement. | ISO 31000 expects its own required or recommended outcomes, which may include legal duties, assurance criteria, control objectives, profiles, or risk methodology. | Translate both sides into a single task register only after labeling which requirement or guidance source each task satisfies. |
|---|
| Evidence and records | ISO/IEC 27005 evidence should show the process operating: owners, decisions, registers, control records, test results, review minutes, audit samples, or corrective actions. | ISO 31000 evidence should match its own proof model, such as regulatory records, attestation evidence, framework profiles, risk analysis, or contractual assurance. | Build an evidence matrix with one row per claim and columns for source, owner, artifact, date, review trigger, and reuse permission. |
|---|
| Timing and cadence | ISO/IEC 27005 timing follows implementation, audit, certification, review, supplier, incident, or change cycles rather than a single universal deadline. | ISO 31000 timing follows the legal effective date, assurance period, framework version, contract milestone, or publication lifecycle that applies to that side. | Track dates separately so an ISO review cycle does not get mistaken for a statutory deadline or assurance reporting period. |
|---|
| Enforcement or assurance route | ISO/IEC 27005 is usually tested through certification audits, internal audits, customer assurance, management review, or governance review, depending on how the organization adopts it. | ISO 31000 may be enforced, audited, attested, assessed, or used voluntarily depending on whether it is law, assurance criteria, a framework, or guidance. | Separate audit readiness from legal compliance and from voluntary framework maturity so executives see the actual consequence of gaps. |
|---|
| Overlap and reuse | ISO/IEC 27005 can supply reusable management-system evidence, control operation records, risk decisions, and review outputs. | ISO 31000 can reuse some of that evidence when the control, process, risk, or duty is genuinely the same. | Reuse evidence only after checking scope, actor, date, data type, service, supplier, and acceptance criteria; otherwise keep separate records. |
|---|
| Practical decision rule | Use ISO/IEC 27005 when the main work is building, operating, reviewing, or proving a management-system or standards-based control process. | Use ISO 31000 when the main work is satisfying that side's law, assurance route, framework outcome, risk method, or external reporting expectation. | If both apply, keep the primary obligation visible and use the other side as supporting structure, not as a substitute source. |
|---|