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Stratified Cost Index

Predicting costs for an incident can be daunting, especially if multiple agencies are involved. The WFDSS application uses the Stratified Cost Index (SCI) as a tool to assist with cost estimation for large fires (greater than 300 acres). Here you can learn about what SCI is and how it works, or you can navigate to the instructions for creating a Stratified Cost Index for an incident.

The SCI uses expenditure data from past fires to estimate expected costs per acre based on fires with similar geospatial characteristics and final burned area. Geospatial characteristics are automatically generated by WFDSS based on the ignition point of the fire. Managers can enter potential fire sizes to calibrate the cost estimates to current conditions, or an SCI is system generated for fires larger than 300 acres. SCI estimates can be used to compare cost trajectories to historical norms, analyze the cost consequences of different fire growth scenarios, and aid in early detection of incidents that have the potential for high costs.

The SCI tool provides two key features to aid in estimating costs. First, users can specify up to four different potential fire sizes to estimate a range of costs based on different fire growth scenarios. These fire sizes could encompass the current burned acreage (if more than 300 acres, the minimum size for SCI estimates to be valid), the most likely expected final fire size, and a worst case scenario of final fire size. If conditions change, a new SCI analysis can provide updated estimates of cost per acre based on a new range of expected final fire size.

A second feature of the SCI is the range of estimated costs per acre reported for a given fire size, based on the historical likelihood of each estimate occurring. This range includes the costs per acre at the 25th percentile, 50th percentile (the median-cost fire), 75th percentile, and 90th percentile level. Each level represents the percent of past fires with similar characteristics that had costs per acre less than the reported estimate. For example, the 90th percentile estimate indicates that 90 percent of similar fires had lower costs per acre than the given SCI estimate. Selecting the appropriate cost per acre estimate depends on incident complexity and risk potential. A cost per acre estimate within the higher range of the SCI may be appropriate if a fire’s high risk potential provides a clear justification for unusually high costs.

Stratified Cost Index (SCI) cost model assists in predicting wildland fire costs for fires starting on federal jurisdiction that exceed 300 acres:

SCI regression models are updated annually. This includes the addition of models for Alaska with the exception of the USDA Forest Service.

SCI helps you to estimate costs per acre for an incident using the following variables, most of which are calculated geospatially and auto-filled based on the incident information provided:

The following rules apply:

NOTE: The WFDSS application automatically generates and accepts SCI for fires over 300 acres that start on federal lands. The SCI is currently processed once a day.

For many agencies, the cost estimate is an indicator of the level of approval required for the strategic decision so, you should update the cost estimate as the incident progresses to ensure that the required level of approval has been documented for the decision. Escalations in fire behavior and/or complexity may significantly change cost estimates and require approval of a new decision at a higher organization level.


In This Section


Creating a Stratified Cost Index (SCI)

Editing and Accepting an SCI

Copying an SCI

Viewing SCI Details

Deleting an SCI

See Also

Incident Quick Search

Generating KMZ Files from the Incident List

Incident Setup

Incident Ownership

About Relative Risk

Organization Assessment

Management Action Points

Estimating Final Cost for an Incident

Situation Assessment

About the Assessment Tab

Incident Objectives and Requirements

Course of Action

About the Cost Tab

Estimating Final Cost for an Incident

Adding Incident Notes

Declaring an Incident Out


Field Descriptions

Glossary Resources

Spatial Data Reference

Landscape Data Source Reference

Relative Risk Reference

Organization Assessment Reference

Fire Behavior Reference

About the WFDSS Decision Editors