Continuous Assurance: How to Manage Risk Across Mainframe Modernization

Summary

Modernization creates a difficult balancing act. The systems most important to the business need to evolve, but every alteration can introduce new security, compliance, and operational risks. Moving faster depends on knowing that critical systems remain protected as the technology around them changes.

This is especially important in mainframe environments, where organizations rely on systems that support sensitive data and essential business processes. As these environments become more integrated with modern technologies, CIOs need a current view of risk and a way to determine whether existing protections are keeping pace.

That is where continuous assurance comes in. It gives technology leaders a way to continually evaluate the security and resilience of critical systems as those environments develop.

The concept can be understood through four practical questions:

1. Do we know where we’re exposed?
2. Are our controls working as intended?
3. Can we demonstrate compliance?
4. Can we recover when something goes wrong?

Together, these questions provide a practical framework for understanding what continuous assurance looks like in a modernizing mainframe environment.

Do we know where we’re exposed?

Security controls remain essential, but modernization is changing the environment they need to protect. As organizations introduce AI into applications, development workflows, and business processes, they create new connections to mainframe data and systems. Combined with APIs, open-source components, and broader integration, these changes can reshape where vulnerabilities emerge and how critical systems are accessed.

Continuous assurance helps organizations maintain a current view of that changing risk and understand which vulnerabilities warrant attention.

Visibility alone, however, is not enough. A long list of findings provides limited insight into which issues could materially affect a critical application or business process. Continouous assurance helps teams prioritize exposure based on potential impact, giving security and IT teams a stronger basis for directing resources where they matter most.

Are our controls working as intended?

Knowing that controls exist is different from having current evidence that they are working as intended.

Periodic assessments provide a useful snapshot that can quickly lose relevance as modernization progresses. That creates an assurance gap between having protections in place and being able to continuously validate that risk remains under control.

Continuous validation helps close that gap by testing whether controls perform as expected and whether remediation has actually reduced risk. As issues are addressed, IT teams can reassess the environment and maintain a more accurate view of their security posture. That validation provides a stronger basis for deciding when modernization can move forward and where additional safeguards may be needed.

Can we demonstrate compliance? 

Modernization can also affect how companies establish compliance. New technologies and access patterns may introduce new requirements or alter how existing controls are documented.

Continuous assurance helps connect technical risk with the evidence companies need for governance and regulatory oversight. That becomes especially valuable when the same control supports multiple obligations, allowing security and compliance teams to maintain current, audit-ready evidence that controls are working as intended, without reconstructing that story for every audit or review.

A more continuous approach can make that evidence easier to maintain as systems transition. It also provides a clearer record of how risk decisions were made and whether controls continue to support the obligations attached to critical systems.

Can we recover when something goes wrong?

Even well-protected environments can experience disruption. Continuous assurance, therefore, needs to account for what happens when a critical system becomes unavailable or compromised.

Companies need evidence that recovery plans still reflect the systems they operate today. As modernization introduces new dependencies across the technology environment, assumptions about how quickly critical services can be restored may change as well.

Continuous assurance can help teams test those assumptions and keep resilience plans aligned with the current environment. Regular validation can also reveal whether recovery expectations hold up in practice before an actual disruption puts them to the test.

Making assurance continuous

These key questions make assurance a practical decision-making tool, giving technology decision-makers a clearer understanding of risk and its implications for upcoming modernization decisions.

Rocket^®  z/Assurance^™ portfolio puts this approach into practice by combining security expertise and technology across the mainframe environment. By maintaining a current view of risk as systems evolve, businesses can better understand how well their protections are holding up throughout modernization.

For technology and security teams, that can mean moving faster when risk is well understood and exercising greater caution when it is warranted. Continuous assurance ultimately helps them determine which risks are worth taking so they can keep critical modernization initiatives moving forward.