A Hierarchical Access Control Model : ROAM – Role-Based Access Control (RBAC) is a widely adopted model that assigns appropriate permissions to users based on their organizational roles. While RBAC can be integrated with HR databases for dynamic access management and is considered a powerful access control mechanism, its implementation often proves difficult for small businesses and startups due to limited resources and system complexity.
Moreover, these organizations often struggle to enforce separation of duties (SoD), which results in overlooking the importance of access control and frequently failing to uphold the principle of least privilege (PoLP).
To address these practical challenges, I propose ROAM, a simplified and intuitive hierarchical access control model designed to help organizations of all sizes apply structured and secure permission management.
1. What is ROAM?
ROAM stands for Responsible, Operator, Admin, and Member. It is a role-based framework that categorizes users within information and security systems into four clearly defined levels, based on their responsibilities.
Each level is defined as follows:
- Responsible: The final authority overseeing system operations, including policy approval and audit response.
- Operator: The technician responsible for configuration changes and operational tasks, such as log analysis and incident handling.
- Admin: The administrator who manages accounts and permissions, including user provisioning and privilege adjustment.
- Member: The general user who consumes system functions, such as accessing information or performing business tasks.
By clearly defining privileges at each ROAM level during system deployment or change, organizations can prevent privilege abuse and apply security settings as part of an implementation checklist.
ROAM should be adopted as a baseline access policy in any system. More granular permissions, such as CRUD (Create, Read, Update, Delete) actions, can be further defined through extended profiles built on top of the ROAM foundation.
2. Rationale and Practical Applicability of the ROAM Model
ROAM not only offers a practical alternative for organizations lacking mature RBAC systems but also provides a foundation for future dynamic RBAC implementations. Its benefits include:
(1) Enforcing the Principle of Least Privilege
Excessive privileges are a direct security risk. By assigning only necessary permissions based on hierarchical roles, the impact of potential breaches can be significantly minimized.
- Users receive only the minimum access required for their job functions.
- It reduces the risk of privilege misuse and protects against insider threats.
(2) Enhancing Security Through Separation of Duties
Clearly separating responsibilities—such as between operators and auditors, or developers and admins—helps reduce the likelihood of insider threats and conflicts of interest.
- Conflicting permissions are avoided, and accountability becomes clearer during security incidents.
- For instance, separating the approver from the executor makes audit responses more reliable.
(3) Clear Role Definitions and Collaborative Efficiency
Ambiguous or overlapping responsibilities can lead to confusion. ROAM eliminates these “gray zones” by clearly defining roles.
- Collaboration between departments is improved due to well-defined boundaries.
- Communication overhead and misunderstandings regarding access scopes are reduced.
(4) High Security Impact with Minimal Resources
Even without a formal access control system, applying the ROAM structure alone brings significant security improvements.
- ROAM is easy to implement and integrates seamlessly with existing systems.
- Ideal for startups or SMEs with limited security resources.
3. Conclusion
The term ROAM is not an official standard but a practical framework intended to unify how access roles are structured across different organizations and projects. In real-world operations, it serves as a base model that can be flexibly expanded through custom profiles to define detailed CRUD permissions.
ROAM is also scalable. Organizations with limited resources can start by applying just two levels—Operator and Admin—to introduce a minimum standard of role separation.
However, regardless of resource limitations, the fundamental principles must be maintained:
Operators should never manipulate logs, and Admins should not make uncontrolled changes to production environments.
Separation of duties is not a luxury but the final safeguard of security, rooted in balance, oversight, and accountability.
Note: ROAM is not an official security standard, but a proposed structure developed in response to real-world operational needs.