Service disruptions are often a result of ___.

• A. A scheduled shutdown
• B. An unscheduled shutdown
• C. An accident
• D. A staff shortage

Answer: (B)

Unplanned outages disrupt service because they happen without notice and interrupt normal operation—typically due to equipment failures, faults, or power issues. Planned shutdowns are intentional and scheduled, so they’re expected and prepared for rather than considered disruptions. While accidents or staff shortages can cause problems, they don’t represent the frequent, abrupt interruptions that characterize an unscheduled shutdown.