SR controls

SR controls are documented security requirements that specify how systems, data, and interfaces must be protected. In regulated or contract-driven environments, the term usually refers to a defined set of security requirements from a formal standard or customer flow-down that suppliers and internal teams must interpret, implement, and maintain.

What SR controls typically include

SR controls commonly cover areas such as:

• Access control and user authentication for manufacturing and business systems
• Network security for OT and IT environments, including segmentation and remote access
• System hardening, patching, and malware protection on shop-floor and enterprise assets
• Data protection, including handling of technical data and production records
• Monitoring, logging, and incident response expectations
• Supplier and third-party access to production systems and data

Each SR control typically states a desired security outcome or requirement (for example, restricting access to specific roles, encrypting data, or logging configuration changes). Organizations then design technical and procedural measures that satisfy the intent of the requirement in their specific environment.

Operational meaning in manufacturing environments

In industrial and manufacturing contexts, SR controls are applied across both OT and IT systems. They influence:

• Configuration of MES, SCADA, PLCs, historians, and plant networks
• How production and quality data are accessed, stored, and transmitted
• Supplier connections to plant systems and shared data repositories
• Change control around configuration, software updates, and security settings

Not every SR control applies in every situation. Organizations often perform a scoping and applicability review, then document how each applicable control is addressed, any tailoring, and any compensating controls used when the control cannot be implemented as written.

Relationship to standards and contracts

The term “SR controls” is frequently used where security requirements are defined by:

• Industry or cybersecurity standards
• Customer or prime contractor security clauses and flow-downs
• Internal corporate security baselines for plants and suppliers

In these cases, SR controls form the checklist of required or expected security behaviors. Suppliers and internal facilities are generally asked to demonstrate how they meet the intent of the applicable controls, and to keep this documented under change control.

Common confusion

• Not the same as general “controls”: SR controls are a subset focused specifically on security requirements, while broader risk or quality controls may address safety, process stability, or product quality.
• Not a specific technology: An SR control is a requirement. Firewalls, access rules, and procedures are examples of measures that can satisfy one or more SR controls.

Context from supplier management

When used in supplier discussions, SR controls usually refer to the security requirements that a supplier is expected to address for the systems and data in scope. Smaller or specialized suppliers may not implement every control exactly as written but are often expected to:

• Determine which SR controls apply to their scope and data
• Implement right-sized technical and procedural measures that meet the intent
• Document applicability decisions, tailoring, and compensating controls
• Maintain this documentation under configuration and change control