ISO 27001 ISMS Skill
ISO 27001 certifies a system (the ISMS), not a checklist — auditors check that you scoped it, assessed
risk, and can justify which Annex A controls you applied or excluded (the Statement of Applicability).
This skill builds that backbone: scope, risk treatment, and a defensible SoA, so certification is a
documented management system rather than a scramble.
Required Inputs
Ask for these only if they aren't already provided:
- ISMS scope — the products, locations, and information assets in scope (and what's deliberately out).
- Context & interested parties — the business, its regulatory/customer security obligations, and key risks.
- Risk approach — how you identify, assess, and treat information-security risk (the SoA flows from the risk assessment, not the other way round).
- Current controls — what's already implemented across the Annex A domains.
Output Format
ISO 27001 ISMS: [organisation]
1. Scope statement — the boundary of the ISMS: assets, locations, exclusions and why.
2. Context & risk — interested parties and their requirements; the risk assessment method and risk acceptance criteria.
3. Statement of Applicability (SoA) — the heart of it: each Annex A control, applicable or not, status, and justification:
(Excluding a control is fine — excluding it without a justification is an audit finding.)
4. Risk treatment plan — the top risks, the treatment (mitigate/accept/transfer/avoid), and the controls that address each.
5. Implementation roadmap — prioritised: mandatory clauses 4–10 (management system) first, then the highest-risk Annex A gaps, with owners and dates.
Programmatic Helper
scripts/soa_coverage.py (stdlib only) scores SoA coverage and flags controls excluded without a
justification (the classic finding):
# soa.json: [{"control":"A.5.1","applicable":true,"status":"met|partial|gap","justification":"..."}, ...]
python3 scripts/soa_coverage.py soa.json
python3 scripts/soa_coverage.py soa.json --json
Quality Checks
Anti-Patterns
Based On
ISO/IEC 27001 (ISMS clauses 4–10) and Annex A control set + the Statement of Applicability requirement.
Example Trigger Phrases
- "Scope an ISMS."
- "Build a Statement of Applicability."
- "Prepare for ISO 27001 certification."