The National Incident Management System (NIMS) was created in 2003 to help federal, state, and local emergency response organizations coordinate their actions. By standardizing response time and type, NIMS seeks to reduce inefficient or redundant actions while placing help in its area of maximum benefit.
At the moment, there have been only three original studies on the subject, each of which showed similar results; the NIMS system is a good start to standardization, but still has flaws in its implementation. Specifically, the federal aspect of NIMS means that in most cases, federal resources allocated to disaster or emergency response will be held back for "major," or "significant" emergencies; the implication -- explicitly stated in one of the studies -- is that the current focus on terrorist-related activities will overshadow natural emergencies, such as hurricanes, floods, and tornadoes.
Another problem is the decreased functionality of local response teams. With specialized teams intended to respond at various levels of threat, local teams might not be trained or ready to respond as quickly as they might otherwise. Although NIMS is intended to provide fast and efficient help, it might also create a dependency in local response, making reaction to disaster slower instead of faster.
Finally, disaster can break down communications, and without designated lines to the federal government, local response teams might not know which areas to focus on. In the case of fast-response, local teams always need to know who is responding and to which emergency, so as not to leave people stranded or in danger.