"A preliminary statement of work prepared by the Primary Department/Agency (D/A) of an Emergency Support Function prior to an event (e.g., major disaster or emergency). The key components of a PSOW are the scope of work (e.g., specific tasks to be performed, requirements or criteria to be followed) and a projected cost estimate. Preparation of the PSOW is the first step in the development of a Pre-Scripted Mission Assignment". (FEMA, Mission Assignment SOPs Operating Draft, July 2007, p. 58)