4-22. Within the joint field office, ESF coordinators analyze the requirements and capabilities in coordination with the federal coordinating officer and DCO. Beginning with the DCO and continuing through the chain of command, each request for assistance receives an evaluation based on factors of legality, lethality, risk, cost, appropriateness, and impact on readiness. The staff supporting the DCO (known as the defense coordinating element) translates the mission assignment into a mission tasking order for the joint task force. Ideally, the federal coordinating officer and DCO determine the capabilities needed, allowing flexibility for command and control arrangements. The joint task force commander translates the mission tasking order into an operation order. The Geographic Combatant Commander decides whether to commit a standing joint task force. The Army Service Component Commander (ASCC) may employ a contingency command post as a joint task force or land component command. Conversely, the ASCC may designate an incoming headquarters as the joint task force or land component command. Federal military forces receive their missions when they arrive in the operational area.