Which of the following is NOT a characteristic of an effective Incident Command System?

An effective Incident Command System (ICS) is characterized by clear structures that enhance coordination and efficiency during incidents. The point about simultaneous command from multiple agencies directly contradicts the fundamental principle of ICS, which is built on establishing a single command structure. This single command is essential for maintaining clarity in leadership, ensuring that decisions are made efficiently and effectively without confusion over authority.

In contrast, other characteristics such as fixed roles and responsibilities help in delineating tasks and maintaining accountability among responders. Standardized communication protocols are critical for ensuring that all parties involved can easily share information and understand instructions, which is vital during emergencies. Furthermore, flexibility to adapt to incidents of any size is fundamental; ICS is designed to scale its response and resources according to the specific needs of each situation, allowing for more effective management regardless of incident complexity.

Overall, the effective functioning of the ICS hinges on clear authority and streamlined command, which is compromised when multiple agencies attempt to exercise command simultaneously.