1.1 What is the Ontario Incident Management System (IMS)?

Ontario Incident Management System (IMS) is designed to be a response system, but it can be used to manage all stages of an incident. It is created to give communities and organizations a common framework to communicate, coordinate and collaborate during an incident response.

An incident is an occurrence or event that requires a coordinated response by emergency services or other responders to protect people, property and the environment. Whether an incident is small or large, IMS can help communities and organizations work together more effectively and efficiently.

IMS provides guidance on all aspects of coordinating an incident response, including:

  • support to the site
  • coordination of incident response efforts
  • command of incident response efforts
  • communication

IMS can be used at the site of an incident, for a planned event, in an emergency operations centre (EOC) or a designated location (for non-site-based incidents) where incident coordination and support take place. IMS is flexible and can be used in both small and large incidents.

1.2 Why use IMS?

Every day, communities and organizations in Ontario work together to respond to incidents and to plan events. Their success depends on the ability to communicate, coordinate and collaborate with one another.

IMS helps incident response organizations respond effectively and efficiently by:

  • providing common structures, systems and roles
  • helping incident response organizations communicate clearly through the use of common terms and concepts
  • creating a flexible framework that can adapt to any level or type of incident

IMS is an important element in building a comprehensive and effective emergency management program; one that includes IMS in its plans, procedures, training and exercises. IMS can help communities and organizations prepare for incidents and manage planned events.

1.3 Who is it for?

IMS can be used by:

All levels of government, Indigenous partners, nongovernmental organizations (NGOs) and private sector partners

Everyone involved in an incident response including, but not limited to:

  • Responders at the site of an incident. This includes first responders (paramedic, police and fire services) as well as personnel from social services and public works.
  • Personnel (such as leadership, incident responders, volunteers etc.) who provide support to the site(s) or coordinate a non-site-based incident in an EOC.
  • Personnel involved in creating and sharing official communications. This can include media releases and social media communications.
  • Organizations and personnel managing resources such as emergency shelters and reception centres.

1.4 When to use IMS

IMS can be used to manage the following:

  • severe winter weather
  • hazardous materials incident
  • fire/explosion
  • flood
  • food contamination
  • infectious disease outbreak
  • nuclear incident
  • public safety incident
  • humanitarian emergencies
  • transportation emergencies
  • electrical energy failure
  • structure failure
  • incidents resulting in mass casualties
  • cyber-attack
  • planned events (such as parades, celebrations, official events)
  • multiple incidents (which can include related cascading hazards such as mudslides after flooding or unrelated hazards such as a fire during an ice storm)
  • long-term incidents (which may not have a defined beginning or end)

IMS provides the foundation to establish a common incident management structure. It is important to note that not every section in an incident management structure is needed for every incident. This may happen for several reasons as discussed in Section 5 – Response escalation guidelines.

Communities and organizations can also use IMS to build their own standard operating procedures that reflect responsibilities, resources and legislative requirements that are specific to that community or organization.

1.5 Where does IMS come from?

The Ontario Incident Management System (IMS) was first developed in 2008 to provide a standardized approach to incident management. It was based on and aligned with the United States National Incident Management System (NIMS). IMS is in line with a global shift in incident response to develop ways to help communities and organizations work together more effectively and efficiently during an incident.

The second version of the Incident Management System (also known as IMS 2.0) builds upon and replaces the first version, Incident Management System Doctrine for Ontario. IMS 2.0 has addressed several recommendations from The Elliot Lake Inquiry to “put in place strategies that will increase the acceptance and actual use of the Incident Management System (IMS) – including simplifying its language…”footnote 2 It also reflects updates to NIMS, global best practices and lessons learned by Ontario’s emergency response community. A list of references used to develop IMS 2.0 can be found in Appendix C – References.

1.6 How does the Incident Command System (ICS) relate to IMS?

The Incident Command System (ICS) is one of the key building blocks of the Incident Management System. ICS is a site-specific response system that was developed in the 1970s to manage the response to wildfires in California. It has been adopted by communities and organizations worldwide to manage incidents and planned events through the use of commonly used practices, structures and terms.

It is important to note that ICS is site-specific; therefore, it was not designed for EOCs, non-site-specific responses or to meet the demands of a complex long-term health emergency.footnote 3 In contrast, Ontario’s IMS is designed to meet the needs of all levels of response, ranging from the site(s) to EOCs to the complex network coordination within the health care sector. Ontario’s IMS also reflects best practices worldwide.

The site-based guidance in IMS 2.0 is compatible with NIMS-ICS and the ICS taught by ICS-Canada. It is important to note that while there is a standardized structure with commonly used practices, structures and terms, there are several interoperable variations of ICS (with no single official ICS).

The Government of Ontario has ensured that IMS is interoperable with incident management systems in other provinces and territories in Canada. It also reflects needs specific to Ontario, including governance structures and legislative processes.

1.7 Accountability

All responders involved in an incident should carry out their duties with diligence and respect for those affected by the incident and for the community at large. Governments and organizations also have legal obligations to the people they serve.

IMS ensures accountability by defining clear roles and responsibilities. Incident responders involved in the coordination and command function are responsible for tracking:

  • all resources (personnel and equipment) assigned to an incident
  • the safety of all incident response personnel and individuals affected by an incident

All incident responders should document their actions taken throughout an incident by filling out standardized IMS forms. Documentation ensures that actions throughout an incident are captured and can be accounted for if asked to provide reasoning.

1.8 Key terms and definitions

Several key terms used throughout the document are listed and defined below. A complete list of terms and definitions can be found in Appendix A – IMS glossary and definitions.

Complex incident: This type of incident involves many factors which cannot be easily analyzed and understood. They may be prolonged, large-scale and/or involve multiple jurisdictions.

Emergency operations centre (EOC): An EOC is a designated location where personnel representing communities and organizations come together to support site response efforts. Activities in an EOC include managing and providing information and resources, long-term planning and other forms of coordination. In some non-site-based incidents such as widespread flooding, an EOC may coordinate and command direct response efforts.

Function: A function is a set of related tasks and responsibilities. Incident management is divided into six main functions: coordination and command, operations, planning, logistics, finance and administration and public information management. In some incidents, additional functions may need to be carried out. This can include intelligence, investigations, scientific/technical, emergency social services and continuity of operations. Other functions may need to be considered depending on the size and nature of an incident.

Incident action plan (IAP): A verbal or written plan which describes how an incident will be managed. It includes incident objectives, strategies and tactics. In a simple incident, objectives, strategies and tactics may be determined by the incident commander or EOC director. In a complex incident, a network of organizations may work together to determine objectives, strategies and tactics. The written IAP is coordinated by the planning section and explains how incident responders will work together and utilize resources to achieve the response objectives.

Incident: An occurrence or event that requires a coordinated response by emergency services or other responders to protect people, property and the environment.

Responder: Any person who is involved in responding to an incident. They range from first responders from paramedic, police and fire services to personnel from public works, regional conservation authorities and those in an EOC. Personnel from nongovernmental organizations (NGOs) and the private sector may also be involved in an incident response.

Site: The location where an incident is or has happened (e.g. the scene of a high-rise fire or motor vehicle accident). Some incidents, such as ice storms, do not have one single, defined site.


  • footnote[2] Back to paragraph Report of the Elliot Lake Commission of Inquiry, released on October 15, 2014.
  • footnote[3] Back to paragraph For example, the 2003 SARS health emergency is an example of a complex long-term health emergency.