define incident operational period | Law homework help

Define the “Incident Operational Period”.

1.  Who is responsible for establishing these periods, and why?
2.  What transition does the initial response to the next Incident Operational Period signify for an incident?
Use the following supplements to develop your answer:
FEMA – The Planning Process
HHS – see ‘Transitional Management Meeting’
Fire Engineering – Setting Objectives and Strategies 
450-500 words excluding reference, APA format, and minimum of two reference