Organisational Policies - Secure Architecture

The effective adoption of Chapter 04 - Secure Architecture - requires the existence of formal organisational policies that sustain, legitimise and make auditable the application of the practices described here.

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📌 Fundamental note

⚠️ The technical practices of defining trust zones, validating the architecture, justified exceptions and traceability must be supported by approved and published organisational policies.

These policies:

• Formalise responsibilities and technical acceptance criteria;
• Make the governance of the architecture visible throughout the lifecycle;
• Allow objective auditing of architectural decisions and exceptions;
• Support traceability between requirements, architecture and technical evidence.

🧩 This chapter operationalises formal decisions about architecture - the policy defines, the chapter executes.

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🧾 Recommended policies

Policy Name	Mandatory	Application	Minimum expected content
Secure Architecture Policy	✅ Yes	All teams with technical responsibility	Mandatory patterns, definition of trust zones, segmentation, minimum requirements
Technical Design Approval Policy	✅ Yes	Projects with an impact on the architecture	Formal review process, roles and responsibilities, technical acceptance criteria
Architectural Documentation and Versioning Policy	✅ Yes	Systems with L2 or L3 criticality	Diagram rules, controlled versioning, updates on structural changes
Architectural Traceability Policy	✅ Yes	Projects subject to control or audit	Mapping of requirements (ARC-00x) → component → technical control
Policy on Technical Exceptions in Architecture	✅ Yes	Whenever a requirement is not applicable	Formal form, review cycle, compensating plan, validity and technical owner

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📋 Suggested structure of each policy

Each organisational policy must contain:

• Objective and scope (e.g. applies to all L2+ projects);
• Mandatory technical criteria (e.g. ZTCs, checklists, exception model);
• Roles and responsibilities (architecture, security, development, operations);
• Requirement for evidence and traceability (e.g. diagram, validation records);
• Process for reviewing and updating the policy itself (e.g. annual);
• Integration with release processes and technical audit.

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✅ Final recommendations

• These policies must be formal, accessible and approved by the architecture and security areas;
• Their application must be integrated into the lifecycle via templates, gates and CI/CD practices;
• The existence of these policies makes secure architecture viable as an auditable and cross-cutting practice, ensuring traceability and consistency.

📌 Their absence compromises the coherence of technical decisions, the validation of exceptions and the auditability of the architecture - in internal projects as much as in regulated contexts.