NIMS Definitions

Branch—A supervisory level above division, group, or sector, designed to provide span of control at a high level. A branch is usually applied to the operations or logistics sections and is usually identified by a Roman numeral or functional name.

Command Staff—Positions that assume responsibility for key activities at an incident and are not part of the line organization. The command staff is headed by the incident commander. Additional command staff, including the safety officer, public information officer, and liaison officer, report directly to the incident commander. Other command staff positions may be appointed as needed.

Crew—An organized group of firefighters under leadership of a company officer, crew leader, or designated official.

Division—A supervisory level that divides the incident into geographic areas of operational responsibility. Divisions are established when the number of available resources exceeds the span of control of the section or branch chief.

First Responders—First responders include public safety professionals and trained volunteers who respond to and provide services at emergencies where additional skills and resources may be needed to bring the incident to a safe conclusion. First responders, often the first trained personnel to arrive on scene, usually arrive with standard issue protective and tactical equipment, which may not be adequate for intervention. First responders often provide first detailed scene information to managing authorities and other responding agencies. As the incident evolves, first responders may assist with establishment of structured incident command. They may continue to participate in incident stabilization and mitigation under the direction and supervision of highly trained specialists.

General Staff—Senior line positions that supervise the various functions such as operations, planning, logistics, and finance sections. The chief of each section reports directly to the incident commander.

Group—Organization level that divides the incident according to functional levels of operation. Groups perform special functions, often across geographic boundaries such as search and rescue, water supply, ventilation, and interior attack.

Resources—Personnel and major items of equipment, supplies, and facilities that are available for assignment to incident operations. Resources are described by kind and type; their status is maintained until released by supervisory personnel.

Section—Any of four major functional components—operations, planning, logistics, and finance—that comprise general staff. Sections may be subdivided by geographic or functional responsibilities into branches, divisions, or groups.

Sector—An alternate name for geographic or functional assignment, comparable to a division or group.

Single Resource—An individual vehicle and its assigned personnel.

Span of Control—The number of personnel that a supervisor is responsible for. Span of control is often expressed as the ratio of supervisor to personnel. Appropriate IMS span of control ranges between 1:3 and 1:7.

Strike Team—Multiple units, often five in number, of the same resource category that have an assigned strike team leader.

Task Force—Any combination of single resources, but typically two to five, assembled to meet a specific tactical need.

Unified Command—Incident management performed by representatives of several agencies to assure that a consistent response plan is developed and deployed and that all actions are performed in a safe, well-coordinated manner.

Unity of Command—A management concept that assures that each responder has only one direct supervisor.