Which function is essential for maintaining documentation during an incident?

The Planning function is essential for maintaining documentation during an incident because it involves the systematic gathering, organizing, and analysis of information related to the incident response. This function ensures that critical information, such as incident objectives, resource allocations, and situation reports, is documented and updated regularly.

Documentation is crucial as it provides a clear record of decisions made, actions taken, and resources used throughout the incident response process. This helps in maintaining continuity, allows for effective communication among team members, and provides valuable information for after-action reviews which can inform future operations.

While other functions such as Logistics and Operations play significant roles in managing resources and executing response strategies, they do not focus primarily on the comprehensive record-keeping aspect that is central to the Planning function. The Intelligence/Investigations function might deal with gathering information, but it does not encompass the broader scope of documentation and situational awareness that the Planning function fulfills.