External audits by external auditors

1) Purpose of external audit and expected results

• auditor's report (opinion/attestation) with identified comments and recommendations;
• A consistent and traceable CAPA plan with deadlines
• reproducible "audit pack" and traceability of solutions.

2) Terms and framework

Engagement Letter (EL): service contract, defines scope, criteria, period and access rights.
Prepared By Client - a list of materials, dates and formats that the organization prepares.
Test of Design (ToD) - check that the control exists and is described correctly.
Test of Operating Effectiveness (ToE): check that the control works stably in the tested period.
Walkthrough: step-by-step analysis of the process on a selective case.
Reform: independent repetition of the operation/selection by auditors.

3) Principles of successful external verification

Independence and transparency: no conflicts of interest, formal recusals.
Audit-ready by design: artifacts and logs are immutable (WORM), versions and hash receipts are recorded automatically.

Unified position: agreed facts, one speaker "by default."

Privacy and minimum: the rule of "minimum sufficient data," depersonalization.
Calendar and discipline: SLA for responses/uploads, battle-rhythm updates.

4) Roles and RACI

(R — Responsible; A — Accountable; C — Consulted; I — Informed)

5) Engagement Letter

• Scope & Criteria: standards/frameworks (e.g. SOC/ISO/PCI/regulatory requirements), jurisdictions, processes.
• Period under review: reporting period and "cut-off" date.
• Access & Confidentiality: access levels, Data Room rules, NDA.
• Deliverables: report type, findings format, draft and final dates.
• Logistics: communication channels, SLA for answers, interview list.

6) Preparation: PBC list and "audit pack"

PBC-list fixes: list of documents/logs/samples, format (PDF/CSV/JSON), owners and deadlines.
Audit pack is assembled from an unchanging evidence showcase and includes: policies/procedures, system and control map, period metrics, log and configuration selections, scan reports, provider materials, CAPA status of previous checks. Each file is accompanied by a hash receipt and an access log.

7) Audit methodologies and sampling approach

Walkthrough: end-to-end demonstration - from politics to actual logs/tickets/system trail.
ToD: availability and correctness of control (description, owner, frequency, measurability).
ToE: fixed samples per period (risk-based n, stratified by criticality/jurisdictions/roles).
Reform: the auditor reproduces the operation (for example, DSAR export, revocation of access, TTL deletion).
Negative testing: an attempt to bypass control (SoD, ABAC, limits, secret scan).

8) Artifact and evidence management

WORM/Object Lock - prevent overwriting/deletion during the check period.
Integrity: hash chains/merkle anchors, verification logs.
Chain of Custody: who, when and why created/changed/read the file.
Case-based access: access by audit/case number with temporary rights.
Depersonalization: masking/pseudonymization of personal fields.

9) Interaction during inspection

Single window: official channel (inbox/portal) and request numbering.
Answer format: numbered applications, links to artifacts, a brief summary of the data generation method.
Interview: list of speakers, scripts of difficult questions, prohibition of unverified statements.
It-site/online visits: schedule, Data Room, live-protocol questions/promises with owners and deadlines.

10) Findings, report and CAPA

Standard finding structure: criterion → actual → impact → recommendation.
CAPA is issued for each comment: owner, Corrective/Preventive measures, deadlines, resources, success metrics, compensating controls if necessary. All CAPAs fall into GRC, status dashboards and are subject to re-audit upon completion.

11) Work with providers (third parties)

Request dossier: certificates (SOC/ISO/PCI), pentest results, SLA/incidents, list of sub-processors and data locations.
Contractual grounds: the right to audit/questionnaires, the timing of the provision of artifacts, mirror retention and confirmation of removal/destruction.
Escalations: SLA penalties/credits, off-ramp conditions and migration plan for significant violations.

12) External audit performance metrics

On-time PBC:% of PBC positions closed on time (target ≥ 98%).
First-Pass Acceptance:% of materials accepted without modifications.
CAPA On-time:% CAPA closed on maturity.
Repeat Findings (12 months): proportion of repetitions by domain (↓ trend).
Audit-Ready Time: hours to collect the full "audit pack" (target ≤ 8 hours).
Evidence Integrity: 100% pass hash chain/anchor checks.
Vendor Certificate Freshness:% of current certificates from critical providers (100% goal).

13) Dashboards (minimum set)

Engagement Tracker: check stages (Plan → Fieldwork → Draft → Final), SLA requests.
PBC Burndown: Remaining positions by owner/term.
Findings & CAPA: criticality, owners, timing, progress.
Evidence Readiness: presence of WORM/hashes, completeness of packages.
Vendor Assurance: status of provider materials and mirror retentions.
Audit Calendar: future validation/certification windows and preparation.

14) SOP (standard procedures)

SOP-1: Start external audit

Initiate EL → fix scope/period → assign roles and calendar → publish PBC → open Data Room → prepare response templates and one-pagers.

SOP-2: Response to auditor's request

Register a request → appoint an owner → collect and verify data → legal/privacy-review → generate a packet with a hash receipt → send it through the official channel → record a delivery confirmation.

SOP-3: Walkthrough/Reperform

Agree on scenarios → prepare demo environments and masked data → conduct walkthrough → capture conclusions and artifacts in WORM.

SOP-4: Report and CAPA Processing

Classify findings → issue CAPA (SMART) → updates on the Committee → create tasks/escalations → link re-audit and deadlines.

SOP-5: Post-mortem on audit

After 2-4 weeks: process assessment, SLA, evidence quality, template/policy update, improvement plan.

15) Checklists

Before starting

• EL signed, scope/criteria/period defined.
• PBC published and owners/deadlines assigned.
• Data Room is ready, access "by case" is configured.
• One-pagers/charts/glossary prepared.
• Policies/procedures/versions updated.

During fieldwork

• All responses go through a single channel, with a request ID.
• Each file has a hash receipt and an access log entry.
• Interview/demo - by list, with protocol and task owners.
• Controversial interpretations - fix, bring to legal-review.

After the report

• Findings are classified, CAPAs are assigned and approved.
• Deadlines and metrics are established in GRC/dashboards.
• Re-audit assigned to High/Critical.
• Updated SOP/Policies/Control Rules.

16) Antipatterns

"Paper" materials without logs and hash confirmation.
Uncoordinated speakers and conflicting responses.
Manual unloading without immutability and storage chains.
Narrowing scope during inspection without documented addendum.
CAPAs without preventive measures and expiry dates of compensatory controls.
Absence of re-audit and observation for 30-90 days → repeated violations.

17) Maturity model (M0-M4)

M0 Hell-hoc: reactive charges, chaotic responses, no PBC.
M1 Planned: EL/PBC, basic templates, single channel.
M2 Managed: WORM archive, hash receipts, dashboards, SLA.
M3 Integrated: "audit pack" by button, assurance-as-code, repositioning in staging.
M4 Continuous Assurance: predictive KRIs, auto-generation of packages and auto-escalation by time, minimizing manual labor.

18) Related wiki articles

Interaction with regulators and auditors

Risk-Based Audit (RBA)

Continuous Compliance Monitoring (CCM)

Storage of evidence and documentation

Logging and Audit Trail

Remediation Plans (CAPAs)

Re-audits and follow-up

Compliance Policy Change Management

Due Diligence and Outsourcing Risks

Result

External auditing becomes manageable and predictable when evidence is immutable, the process is standardized, roles and timelines are clear, and CAPA closes the loop through re-audit and metrics. This approach reduces the cost of compliance, speeds up inspections and builds trust in the organization.