Estimating cost requirements for the sustainment of real property facilities is a credible and auditable task for the U.S. Department of Defense (DoD) thanks to the Facilities Sustainment Model (FSM), a predictive model developed and maintained by R&K Engineering. This standardized analytical tool is based on commercial practices and academic sources to help planners more accurately forecast future annual financial requirements. This model is an integral component of DoD's real property budgeting process, and is a source and justification of reports and financial requests to Congress.

The Facilities Sustainment Model calculates what should be spent annually on facilities for major repairs, replacement of components, and preventive maintenance.

FSM processes DoD-supplied real property data according to business rules unique to the model. R&K Engineering develops these rules under the auspices of the Configuration/Support Panel for FSM. The rules specify which types of facilities are to be included in the model, the funding organization and fund source for the cost requirements for each facility, and the formulas for calculating the sustainment requirements. Over two dozen reference tables of facility data, codes, and factors are used to support the business rules.

The facility data is projected from three to eight years into the future, with changes to the inventory (such as new construction or disposals) incorporated each year. Cost requirement calculations are made on all facilities in each of the six years. These calculations are based on characteristics of each facility, U.S. Government-supplied inflation rates and area cost factors, and sustainment cost factors based on facility type.

R&K Engineering researches both commercial and military data to prepare cost factors for the sustainment of over 400 different facility categories.

Sustainment cost requirements data is available from FSM at the facility level, the DoD level, and several intermediate levels, and can be arranged by facility type, funding organization, and fund source.