Authority to Operate (ATO)

Authority to Operate (ATO) is a formal management decision that authorizes an information system, application, or operational technology (OT) environment to be placed into operation and to process, store, or transmit data. It reflects an explicit acceptance of the system’s residual cybersecurity risk by a designated authorizing official.

In regulated and defense-related manufacturing contexts, an ATO is commonly associated with government or defense customers and is often aligned with frameworks such as NIST SP 800-53 and the NIST Risk Management Framework (RMF). An ATO decision usually follows completion of a security assessment of the system’s controls, documentation of risks, and agreement on how those risks will be managed.

What an ATO typically includes

While details vary by organization and regulatory environment, an ATO commonly involves:

• Identification and description of the system or environment being authorized (scope and boundaries)
• Documented security controls and a security plan (for example, aligned to NIST SP 800-53 controls)
• Results of security assessment activities, such as vulnerability scans, penetration tests, and control evaluations
• A risk assessment and statement of residual risks that remain after controls are implemented
• A formal authorization decision and signature by a designated authorizing official
• Conditions, limitations, or remediation activities required during the authorization period

An ATO is typically time-bound and may need to be renewed or reissued after significant system changes, new threats, or on a defined review cycle.

ATO in manufacturing and OT environments

In industrial and manufacturing settings, an ATO may apply to systems such as:

• Manufacturing execution systems (MES) hosted in cloud or on-premises environments
• Industrial control systems (ICS), SCADA, and other OT networks handling controlled or sensitive data
• Data platforms used to store or process controlled unclassified information (CUI) for aerospace or defense programs
• Integrated environments where ERP, MES, quality, and engineering systems exchange regulated data

For organizations supporting government or defense contracts, an ATO may be a prerequisite to connect plant systems to government networks, process certain classes of technical data, or host CUI on particular infrastructure. The ATO does not itself certify compliance with a standard; it documents that the identified risks and controls are understood and accepted by the authorizing entity.

Relation to NIST SP 800-53 and RMF

Within the NIST Risk Management Framework, an ATO is the outcome of the authorization step, which comes after categorizing the system, selecting and implementing security controls (often from NIST SP 800-53), and assessing those controls. For manufacturers, especially aerospace and defense suppliers, ATO requirements may appear in contracts or government-hosted environments where plant or engineering systems interface with federal systems or handle federal information.

Common confusion

• ATO vs. compliance: An ATO is not the same as full compliance with a framework such as NIST SP 800-53. An organization can receive an ATO with documented residual risks and partial control implementation, as long as the authorizing official accepts that risk.
• ATO vs. security accreditation: In some contexts, “accreditation” refers to the formal evaluation of a system’s security posture, while the ATO is the management decision that follows. The terms are sometimes used together but describe different parts of the process.
• ATO vs. internal go-live approval: Many manufacturers have internal IT/OT change control or go-live approvals. Those internal approvals may resemble an ATO process but are not the same as a formal ATO issued under a government or NIST-aligned RMF process.

Context from aerospace and defense manufacturing

In aerospace manufacturing and other sectors that handle CUI or federal information, an ATO commonly refers to the government or prime-contractor authorization that permits a contractor’s system to operate for specific data and missions. Organizations often map their cybersecurity controls to NIST SP 800-53 but take a scoped, risk-based approach to control implementation across plants and systems. The ATO records that approach and the associated risk decisions for the in-scope environment.