Step 2B: Rating (Scoring) Target Hazards

Utilizing a rating or scoring system assigned to each property can help to determine which target hazards are the most critical. One simple method is to apply a criticality score ranging from 1–3: Low, moderate, or high. Some experts recommend the use of the Occupancy Vulnerability Assessment Profile (OVAP) score as a method determine and categorize occupancy risks.  OVAP criteria can be more detailed and range from 1–5 (Oliver, D. (2011, November). FireRescue Magazine, 42–47)

Occupancy Vulnerability Assessment Profile Criteria
Criteria Name Description Score
Low Structures that consist of mainly fire-resistive or noncombustible materials 1
Moderate Structures that consist of an ordinary mix of construction materials 2
High Structures that consist of significant wood-frame or heavy timber materials 3
Very High Structures with combustible materials that share walls, attics, etc. 4
Moderate to Extreme Technological or hazmat exposure (CBRN) 5

Table 4

Occupancy types assigned a higher score are considered to be more critical than those with a lower score. A score should be assigned to each of the following categories:

  • Number of occupants/life safety
  • Building construction
  • Impact (including economic) to the community
  • Number of stories
  • Presences of automatic fire suppression/detection systems
  • Overall size (square footage)
  • Number of fire hydrants nearby
  • Level of hazard
  • Building usage

Figure 8: Map showing color-coded areas indicating level of hazard risk in case of incident.Figure 8 is an example of a map depicting various locations of target hazards, based on defined criteria using a scoring system. In this case, properties are color-coded in accordance with their particular score, making it easier to quickly identify those with the highest levels of risk. Another option would be to generate a map depicting only those facilities with the highest levels of risk, rather than all properties and structures.

There are software applications available for developing a GIS-based analysis. ArcGIS® by Esri® is a very powerful GIS application. Departments using ArcGIS for Desktop can obtain the Target Hazard Analysis tool, which has been specifically designed for use by the fire service and other public safety agencies.