Reading the ISO/IEC 27701 (PIMS) Implementation Guide / Random Thoughts on Privacy Management as a Foundation for AI Governance
0 Introduction
Discussions on AI governance inevitably lean toward the model side. Fairness, explainability, hallucinations, and evaluation metrics are all important issues. On the other hand, corporate practice often stumbles first on the data itself, which precedes the model.
What to collect, what to retain, who to pass it to, and when to delete it. If these data practices remain ambiguous, no matter how much you refine the performance or ethics of an AI model, you will eventually hit a wall in terms of regulatory compliance, auditing, and accountability. If the foundation is crumbling, the AI ethics built upon it are nothing more than a castle in the air.
In this article, using the ISO 27701 IMPLEMENTATION GUIDE created jointly by ET CISO and MOS as a guide, I will attempt to organize some random thoughts on how the management model known as the Privacy Information Management System (PIMS) can function at the intersection of AI and law.
1 The Location of the Problem: Principles Exist, but Procedures are Thin
In the GDPR, Japan's Act on the Protection of Personal Information, or recent AI regulatory proposals, the legal principles surrounding personal information and privacy are well-established. Everyone has heard of principles such as purpose limitation, data minimization, transparency, and rights protection. However, when you get down to the corporate level, you immediately realize that concrete procedures are lacking.
As a typical challenge, it is often unclear who in the organization is responsible for privacy management. Is it the CISO, the DPO, or the legal department? There are many cases where the division of roles is ambiguous. Next, the location and flow of data are not understood. Especially in AI development, which handles large amounts of unstructured data, it is rare for an organization to accurately track which datasets contain PII. Furthermore, processing by contractors or beyond the cloud is invisible. When using external models via APIs, it is easy for how data is processed and stored to become a black box. And, in the event of an accident, it is unclear on what basis one can claim that management was appropriate.
The introduction of AI technology dramatically amplifies these weaknesses. AI consumes vast amounts of data, outputs logs as inference results, connects complexly with external services via APIs, and incorporates its own unique timeline of learning, inference, and improvement. The conventional idea of static database management cannot control this dynamic ecosystem.
In this regard, PIMS based on ISO/IEC 27701 can be read as a framework for translating legal principles into auditable operations. This standard is an extension that adds a layer of privacy protection on top of ISO/IEC 27001 and 27002, the international standards for information security management, and provides detailed requirements and guidance with PII controllers and processors in mind. Its essential value lies in the fact that it does not just preach principles to be followed, but presents a management system that should be operational.
2 The Framework of PIMS: It is the Mundane Clauses that Work for AI
The implementation guide repeatedly emphasizes the idea of embedding privacy into business processes themselves, rather than making it an afterthought for compliance. In AI governance, PIMS consists of the following extremely mundane elements, which are the key to effectiveness.
First is scope setting. It clarifies which businesses, locations, systems, and data types are subject to PIMS, and requires justification if there are any exclusions. In AI projects, PoCs tend to proliferate in each department, making it easy for unmanaged 'rogue AI' to emerge. If the scope is designed incorrectly, no matter how fine the regulations are, you will only be mass-producing unmanaged AI.
Second is roles and authorities. The appointment of a DPO or privacy officer, cross-departmental governance structures, and responsibility decomposition like a RACI matrix are required. In AI usage, the interests of legal, security, data departments, and product teams will inevitably clash. Without a clear division of responsibilities, decision-making on risk acceptance will stall, and projects will fail.
Third is data mapping. It is necessary to maintain where PII is, how it flows, where it is processed, where it is transferred, and when it disappears as a data inventory or record of processing activities. Thinking in terms of AI, training data, evaluation data, prompts entered by users, response logs generated by AI, and feedback loops for model improvement must all be on the same map. AI development without a data flow diagram is equivalent to driving blindfolded.
Fourth is operations. This includes organizing legal grounds, consent management, purpose limitation and minimization, retention periods and secure disposal, third-party and contractor management, cross-border transfer management, privacy by design, anonymization and pseudonymization, rights response, and incident response. These are often discussed as AI-specific issues, but in reality, most of them arise as traditional data processing issues. Before AI is special, it is first and foremost data processing.
3 AI Learning is Processing: Reinterpreting with PIMS
Processing in PIMS terminology, based on definitions such as ISO/IEC 29100, is a concept that broadly includes collection, recording, storage, use, disclosure, and erasure. Naturally, pre-training, fine-tuning, and inference in generative AI also fall within its scope.
What is important here is the perspective of viewing learning not as a one-time event, but as a continuous data lifecycle. Model updates, continuous learning, iterative evaluation, and log accumulation are all processes that occur over time. Thus, the design of purpose limitation and retention periods required by PIMS becomes the core of legal risk management.
For example, when generating answers by having RAG refer to internal knowledge, it is not rare for PII to be mixed into the referenced documents. At that time, the development side might explain that it is okay because the model itself is not being trained, but this is a dangerous perception from a legal and compliance perspective. As long as there is a series of processes to acquire data for inference, vectorize it, hold it as an index, and send it to an external API, the processing is continuing.
The PIMS approach requires visualizing the location of PII here, recording the purpose of use and legal basis, and controlling the retention period and disposal process. The risk of PII remaining in a vector database or the risk of personal information included in prompts being diverted to the model provider's training data is managed through technical anonymization/pseudonymization controls and contractual prohibitions on unauthorized use. In the end, the discussion is not about magical AI theory, but is brought back to mundane and solid data governance.
4 AI is Outside: Vendor Management and Cross-Border Transfer Become Core
Modern AI development and use are difficult to establish without external models and cloud infrastructure. Companies that develop all models from scratch in-house are exceptional, and many companies are in the position of users or integrators using other companies' AI models. Therefore, third-party and contractor management in PIMS is not a peripheral issue, but a core issue of AI governance.
The implementation guide also emphasizes vendor due diligence, the conclusion of data processing agreements, the securing of audit rights, the management of sub-processors, and notification obligations. In the AI service supply chain, model providers, cloud operators, monitoring tool providers, and annotation companies are complexly linked, so if you are satisfied with looking only at primary contractors, you will miss the actual site of data processing.
Also, cross-border transfer management is unavoidable. Where are the inference servers for the LLM being used? In which region are prompts and logs stored? Which country's engineers can access the data for customer support? Understanding these is essential for compliance with the GDPR and Japan's Act on the Protection of Personal Information.
The PIMS framework requires translating the requirements of each jurisdiction into design items for transfer, rather than abstract discussions. This work is not about the lofty principles favored in AI regulatory discussions, but about the gritty coordination of contract practice and system architecture.
5 Without Audit Trails, Accountability Cannot Begin
A typical pattern where discussions on AI and law go in circles is that the conclusion that accountability must be fulfilled comes first, but when an accident actually occurs, there is no evidence for explanation. Logs, judgment records, change history, evaluation results—none of these exist anywhere.
PIMS places documentation and auditability at the core of the system. Internal audits, management reviews, KPI setting, non-conformity and corrective actions, and continuous improvement through the PDCA cycle may seem like boring compliance rituals at first glance. However, in the world of AI, this ritual is the only means to enable actual responsibility distribution.
In particular, accidents such as rights infringement or information leakage by generative AI often occur not as simple, one-off bugs, but as a complex combination of multiple factors. The quality of training data, prompt engineering, guardrail settings, operator authority settings, and specification changes on the vendor side are complexly intertwined.
What is needed here is not a beautiful legal theory about causality, but the reconstructibility of the timeline: when, who, based on what, with what settings, using what data, and with what judgment it was operated. The change management and incident management required by PIMS are equivalent to saying that this reconstructibility should be created in the form of management documents and logs. Without an audit trail, accountability cannot be established.
6 Conclusion
ISO/IEC 27701 does not replace personal information protection legislation itself, nor does it replace product safety regulations like the EU AI Act. Rather, it should be understood as having a position like an OS for converting the accountability and risk management required by those laws into a form that actually works within an organization.
If you are going to talk about AI governance, before spending time formulating abstract AI ethical principles, you should develop the foundation such as data mapping, role decomposition, contractor management, log design, and incident response flows. It is not flashy, but only when this is in place will high-level discussions such as model fairness and transparency land in the organization as operational requirements.
Note that in the ISO catalog, ISO/IEC 27701:2019 is marked as Withdrawn, and ISO/IEC 27701:2025 is indicated as the new version. The concepts of privacy and technical requirements are also dynamic, just like AI technology. That is precisely why the strength of a management system that continues to follow changes through PDCA, rather than a fixed view of rules that are set once and finished, comes into play. In an era where AI evolves too quickly, the strongest thing in the end is a solid management model that can withstand change.
Reference Materials
1 ET CISO x MOS 'ISO 27701 IMPLEMENTATION GUIDE'
2 International Organization for Standardization, ISO/IEC 27701:2019 Security techniques — Extension to ISO/IEC 27001 and ISO/IEC 27002 for privacy information management — Requirements and guidelines (August 2019, Withdrawn in ISO catalog) and ISO/IEC 27701:2025 (Last accessed January 16, 2026)
3 International Organization for Standardization, ISO/IEC 27001 (ISMS Requirements) (Last accessed January 16, 2026)
4 International Organization for Standardization, ISO/IEC 29100:2024 (Privacy framework) (Last accessed January 16, 2026)
5 International Organization for Standardization, ISO/IEC 42001:2023 (AI management system) (Last accessed January 16, 2026)
6 Daiki Yanagidaira 'AI and Medicine / The Problem of Responsibility Attribution in Medical AI — Random Thoughts on the Direction of Legal Governance Indicated by the TRUST Framework' (December 28, 2025, Last accessed January 16, 2026)
(Magazine) 'AI and Law - Random Thoughts'
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