Which type of disaster recovery plan (DRP) testing carries the MOST operational risk?

Cutover (also called full interruption) testing involves actually shutting down primary systems and failing over completely to the disaster recovery environment, meaning the organization runs entirely on the DR site during the test. If the DR site fails or performs inadequately, real business operations are disrupted with no fallback, making it the highest-risk DR test type. This is in contrast to parallel testing, where both environments run simultaneously and production is never fully abandoned.

Walkthrough testing (also called a structured walk-through) is a low-risk, paper-based exercise where team members review the DRP document step-by-step to identify gaps, with no systems actually being moved or activated.

Tabletop testing is a discussion-based simulation where stakeholders talk through their response to a hypothetical scenario without touching any live systems, posing no operational risk whatsoever.

Parallel testing activates the DR site and runs it simultaneously alongside the production environment, so production operations remain fully intact and unaffected if the DR environment encounters problems, making it significantly lower risk than a cutover.