A fishbone diagram is a visual tool that helps in identifying the cause and effect relationships that contribute to a particular event or incident. It is beneficial for pinpointing why control failures occurred during a security incident, as it forces the analysis team to explore multiple dimensions of potential failure points. Event tree analysis is used for probabilistic risk assessment but does not focus specifically on control failures. Pareto charts are useful for prioritizing issues based on their severity but don't establish cause-and-effect relationships. A Gantt chart is a project management tool for scheduling and doesn't apply to the analysis of control failures.