Which situation does not require XYZ to inform other systems of an issue?

In the context of operational procedures within the electric power sector, the situation where system operations staff is below minimum requirements does not necessitate informing other systems. This is primarily because issues related to staffing are typically managed internally within the organization and may not immediately impact the larger interconnected system or require external notifications.

In contrast, the other situations involve critical operational challenges that could directly affect system reliability and the safety of the electrical grid. For instance, anticipating insufficient capacity purchases represents a potential shortfall that could lead to power shortages, which definitely requires dissemination of information to other systems for proactive management. Discovering vandalism at a critical facility poses a security threat and could compromise the integrity of the power supply, necessitating alerts to ensure a coordinated response. Similarly, implementing a voltage reduction usually indicates a response to grid stress and affects overall system stability, warranting communication with related systems to manage implications and ensure synchronized operations.

Thus, while all the scenarios are relevant to system operations, the issue of staffing is considered an internal matter that is more appropriately addressed within the organization rather than communicated externally.