Cross-training is the practice of preparing multiple staff members to perform critical operational tasks, such as restoring backups, restarting services, or approving recovery steps. In cyber security, it matters because many defenses and recovery plans fail when only one person knows how a system really works.
Attackers often exploit this kind of dependence indirectly: ransomware, destructive malware, or an employee absence can turn a technical incident into a staffing crisis. Cross-training reduces that risk by creating backup capability for key roles, improving continuity during incidents, and making recovery procedures more reliable. It is a practical resilience control, not just an HR exercise.