Lesson Summary
FEMA Emergency Management Institute

Course: IS-100 - Incident Command System (ICS) 100 Training
Lesson 2: ICS Features and Principles

Lesson Overview

The ICS Features and Principles lesson introduces you to:

By the end of this lesson, you should be able to:


ICS Features

As you learned in the previous lesson, ICS is based on proven management principles, which contribute to the strength and efficiency of the overall system.

ICS principles are implemented through a wide range of management features including the use of common terminology and clear text, and a modular organizational structure.

ICS emphasizes effective planning, including management by objectives and reliance on an Incident Action Plan.

ICS helps ensure full utilization of all incident resources by:

The ICS features related to command structure include chain of command and unity of command as well as, unified command and transfer of command. Formal transfer of command occurs whenever leadership changes.

Through accountability and mobilization, ICS helps ensure that resources are on hand and ready.

And, finally ICS supports responders and decisionmakers by providing the data they need through effective information and intelligence management.

This lesson covers each of these ICS features in detail.


Common Terminology and Clear Text

The ability to communicate within the ICS is absolutely critical. An essential method for ensuring the ability to communicate is by using common terminology and clear text.

A critical part of an effective multiagency incident management system is for all communications to be in plain English. That is, use clear text. Do not use radio codes, agency-specific codes, or jargon.

ICS establishes common terminology allowing diverse incident management and support entities to work together. Common terminology helps to define:

Each of the above areas will be covered in more detail in this and the remaining lessons.


Modular Organization

The ICS organizational structure develops in a top-down, modular fashion that is based on the size and complexity of the incident, as well as the specifics of the hazard environment created by the incident. As incident complexity increases, the organization expands from the top down as functional responsibilities are delegated.

The ICS organizational structure is flexible. When needed, separate functional elements can be established and subdivided to enhance internal organizational management and external coordination. As the ICS organizational structure expands, the number of management positions also expands to adequately address the requirements of the incident.

In ICS, only those functions or positions necessary for a particular incident will be filled.


Management by Objectives

All levels of a growing ICS organization must have a clear understanding of the functional actions required to manage the incident. Management by objectives is an approach used to communicate functional actions throughout the entire ICS organization. It can be accomplished through the incident action planning process, which includes the following steps:

Step 1: Understand agency policy and direction.
Step 2: Assess incident situation.
Step 3: Establish incident objectives.
Step 4: Select appropriate strategy or strategies to achieve objectives.
Step 5: Perform tactical direction (applying tactics appropriate to the strategy, assigning the right resources, and monitoring their performance).
Step 6: Provide necessary followup (changing strategy or tactics, adding or subtracting resources, etc.).


Reliance on an Incident Action Plan

In ICS, considerable emphasis is placed on developing effective Incident Action Plans.

An Incident Action Plan (IAP) is an oral or written plan containing general objectives reflecting the overall strategy for managing an incident. An IAP includes the identification of operational resources and assignments and may include attachments that provide additional direction.

Every incident must have a verbal or written Incident Action Plan. The purpose of this plan is to provide all incident supervisory personnel with direction for actions to be implemented during the operational period identified in the plan.

Incident Action Plans include the measurable strategic operations to be achieved and are prepared around a timeframe called an Operational Period.

Incident Action Plans provide a coherent means of communicating the overall incident objectives in the context of both operational and support activities. The plan may be oral or written except for hazardous materials incidents, which require a written IAP.

At the simplest level, all Incident Action Plans must have four elements:


Manageable Span of Control

Another basic ICS feature concerns the supervisory structure of the organization.

Span of control pertains to the number of individuals or resources that one supervisor can manage effectively during emergency response incidents or special events. Maintaining an effective span of control is particularly important on incidents where safety and accountability are a top priority.

Span of control is the key to effective and efficient incident management. The type of incident, nature of the task, hazards and safety factors, and distances between personnel and resources all influence span of control considerations.

Maintaining adequate span of control throughout the ICS organization is very important.

Effective span of control on incidents may vary from three (3) to seven (7), and a ratio of one (1) supervisor to five (5) reporting elements is recommended.

If the number of reporting elements falls outside of these ranges, expansion or consolidation of the organization may be necessary. There may be exceptions, usually in lower-risk assignments or where resources work in close proximity to each other.


Predesignated Incident Locations and Facilities

Incident activities may be accomplished from a variety of operational locations and support facilities. Facilities will be identified and established by the Incident Commander depending on the requirements and complexity of the incident or event.

It is important to know and understand the names and functions of the principal ICS facilities.


Incident Facilities Virtual Tour

The Incident Command Post, or ICP, is the location from which the Incident Commander oversees all incident operations. There is generally only one ICP for each incident or event, but it may change locations during the event. Every incident or event must have some form of an Incident Command Post. The ICP may be located in a vehicle, trailer, tent, or within a building. The ICP will be positioned outside of the present and potential hazard zone but close enough to the incident to maintain command. The ICP will be designated by the name of the incident, e.g., Trail Creek ICP.

Staging Areas are temporary locations at an incident where personnel and equipment are kept while waiting for tactical assignments. The resources in the Staging Area are always in available status. Staging Areas should be located close enough to the incident for a timely response, but far enough away to be out of the immediate impact zone. There may be more than one Staging Area at an incident. Staging Areas can be collocated with the ICP, Bases, Camps, Helibases, or Helispots.

A Base is the location from which primary logistics and administrative functions are coordinated and administered. The Base may be collocated with the Incident Command Post. There is only one Base per incident, and it is designated by the incident name. The Base is established and managed by the Logistics Section. The resources in the Base are always out-of-service.

A Camp is the location where resources may be kept to support incident operations if a Base is not accessible to all resources. Camps are temporary locations within the general incident area, which are equipped and staffed to provide food, water, sleeping areas, and sanitary services. Camps are designated by geographic location or number. Multiple Camps may be used, but not all incidents will have Camps.

A Helibase is the location from which helicopter-centered air operations are conducted. Helibases are generally used on a more long-term basis and include such services as fueling and maintenance. The Helibase is usually designated by the name of the incident, e.g. Trail Creek Helibase.

Helispots are more temporary locations at the incident, where helicopters can safely land and take off. Multiple Helispots may be used.


Incident Facility Map Symbols

In ICS, it is important to be able to identify the map symbols associated with the basic incident facilities. The map symbols used to represent each of the six basic ICS facilities are:

On a map, the ICP location appears as a green and white square.

The standard symbol for identifying Staging Areas is an uppercase S in a circle.

The standard symbol for identifying a Base is an uppercase B in a circle.

The standard symbol for identifying a Camp is a C in a circle, a Helibase is an H in a circle, and a Helispot is a black circle with H, a dash, and a numeric identifier.


Resource Management

ICS resources can be factored into two categories:

Tactical resources are always classified as one of the following:

Maintaining an accurate and up-to-date picture of resource utilization is a critical component of resource management.

Resource management includes processes for:

It also includes processes for reimbursement for resources, as appropriate.


Integrated Communications

The use of a common communications plan is essential for ensuring that responders can communicate with one another during an incident. Communication equipment, procedures, and systems must operate across jurisdictions (interoperably).

Developing an integrated voice and data communications system, including equipment, systems, and protocols, must occur prior to an incident.

Effective ICS communications include three elements:


Chain of Command and Unity of Command

In the Incident Command System:

The principles clarify reporting relationships and eliminate the confusion caused by multiple, conflicting directives. Incident managers at all levels must be able to control the actions of all personnel under their supervision. These principles do not apply to the exchange of information. Although orders must flow through the chain of command, members of the organization may directly communicate with each other to ask for or share information.

The command function may be carried out in two ways:


Unified Command

A Unified Command may be needed for incidents involving:

If a Unified Command is needed, Incident Commanders representing agencies or jurisdictions that share responsibility for the incident manage the response from a single Incident Command Post.

A Unified Command allows agencies with different legal, geographic, and functional authorities and responsibilities to work together effectively without affecting individual agency authority, responsibility, or accountability. Under a Unified Command, a single, coordinated Incident Action Plan will direct all activities. The Incident Commanders will supervise a single Command and General Staff organization and speak with one voice.


Transfer of Command

The process of moving the responsibility for incident command from one Incident Commander to another is called transfer of command. Transfer of command may take place when:

The transfer of command process always includes a transfer of command briefing, which may be oral, written, or a combination of both.



Effective accountability during incident operations is essential at all jurisdictional levels and within individual functional areas. Individuals must abide by their agency policies and guidelines and any applicable local, tribal, State, or Federal rules and regulations. The following guidelines must be adhered to:



At any incident or event, the situation must be assessed and response planned. Resources must be organized, assigned and directed to accomplish the incident objectives. As they work, resources must be managed to adjust to changing conditions.

Managing resources safely and effectively is the most important consideration at an incident. Therefore, personnel and equipment should respond only when requested or when dispatched by an appropriate authority.


Information and Intelligence Management

The analysis and sharing of information and intelligence is an important component of ICS. The incident management organization must establish a process for gathering, sharing, and managing incident-related information and intelligence.

Intelligence includes not only national security or other types of classified information but also other operational information that may come from a variety of different sources, such as:

  • Risk assessments.
  • Medical intelligence (i.e., surveillance).
  • Weather information.
  • Geospatial data.
  • Structural designs.
  • Toxic contaminant levels.
  • Utilities and public works data.


General Guidelines—Lengthy Assignments

Many incidents last only a short time, and may not require travel. Other deployments may require a lengthy assignment away from home. Below are general guidelines for incidents requiring extended stays or travel:


General Guidelines—Roles and Authorities

In addition to preparing for your travel arrangements, it is important to understand your role and authorities.


Actions Prior to Departure

Upon receiving an incident assignment, your deployment briefing should include, but may not be limited to, the following information:


Check-In at the Incident: Activities

Check-in officially logs you in at the incident. The check-in process and information helps to:


Check-In at the Incident: Locations

Check in only once. Check-in locations may be found at several incident facilities, including:

Note that these locations may not all be activated at every incident.

Check-in information is usually recorded on ICS Form 211, Check-In List.


Initial Incident Briefing

After check-in, locate your incident supervisor and obtain your initial briefing. The briefing information helps you plan your tasks and communicate with others. Briefings received and given should include:


Incident Recordkeeping

All incidents require some form of recordkeeping. Requirements vary depending upon the agencies involved and the nature of the incident. Detailed information on using ICS forms will be covered in other training sessions, or may be found in the Forms Manual.

Below are general guidelines for incident recordkeeping:

If you are expected to be a supervisor:


Communications Discipline

Important considerations related to communications include:


Personal Conduct

Sexual harassment or discrimination of any type and the use of illegal drugs and/or alcohol are prohibited on all incidents. Report all such activities to your supervisor.

Often times, incident response can produce high stress situations. As part of your responsibilities, you may be required to interact with people who have been adversely affected by the incident. It is important to be patient and act in a professional manner at all times.


Incident Demobilization

Agency requirements for demobilization may vary considerably. General demobilization guidelines for all personnel are to: