The Fast Theater Model (FATHM)

Gerald G. Brown, Alan R. Washburn
2007 Military Operations Research  
The Fast Theater Model (FATHM) is an aggregated joint theater combat model that fuses Air Force Air-to-Ground attack sortie optimization with Ground-to-Ground deterministic Lanchester fire-exchange battles using attrition rates derived from the Army's COSAGE model. The modeled FATHM war is conducted in short periods, with Air-to-Ground and Ground-to-Ground actions carried out in parallel. Period-by-period, damaged and destroyed targets may regenerate, and there may be scheduled reinforcements
more » ... ed reinforcements of attacking platforms, munitions, and new targets. The war progresses in phases whose completion depends on threshold levels of target kills in class categories and limits on phase duration. Each phase has a separate COSAGE input file, so the phases may differ strongly from each other. All FATHM inputs and outputs are ASCII flat-files suitable for immediate integration with a host database and spreadsheet analysis. Completion of a full-scale theater scenario requires about ten minutes on a personal computer. Executive summary FATHM is an aggregated joint theater combat model that quickly answers "what if" questions about the numbers and effectiveness of resources committed to battle, particularly attack platforms and munitions. Battle is viewed as consisting of two parts conducted in parallel over a period of weeks or months: the Ground-to-Ground part and the Air-to-Ground part. Sea battle is not represented, nor is air-to-air battle except by assuming that Blue controls the air throughout. Ground-to-air battle is represented only 2 in that air strikes in the Air-to-Ground battle do carry the implication of possible attrition. Battle occurs in phases, with phase transitions depending on battle results as well as minimum and maximum phase durations. The Ground-to-Ground part of FATHM (hereafter simply the Ground model) is a Lanchester system incorporating both direct and indirect fire, with direct fire being reprogrammed to other targets in the event that some direct target is exhausted. The required attrition coefficients are obtained by pre-processing COSAGE killer-victim scoreboards that are appropriate to the phase. As in COSAGE, Red weapons are represented explicitly. The Air-to-Ground part (hereafter simply the Air model) consists of a sequence of sorties by Blue platforms against Red targets. Most platforms are fixed-wing aircraft, but launchers of expensive munitions such as TLAM and ATACMS are also put in this category. This part of FATHM is optimized period-by-period using Linear Programming, very much in the spirit of models such as HEAVY ATTACK and CFAM. Platforms are attrited, but there is no explicit reference to the Red assets that cause the attrition. Attrition rates can therefore depend on time, but not on battle results. The sole influence of Red fixed-wing aircraft in FATHM is to cause diversion of Blue sorties against Red targets such as airfields, and possibly to influence the time-dependent attrition rates that are determined exogenously. Because Blue air superiority is assumed, only platforms involved in direct attack are modeled (SEAD, CAP, and ECM, in particular, are not modeled). The Air model keeps track of munitions expenditure, and will respect any munitions constraints that are imposed. Indeed, one of the purposes of FATHM is to measure sensitivity to such constraints. The FATHM objective function flexibly acknowledges the importance of • Ending the current phase quickly; • Assuring an equitable distribution of effort over the services; • Avoiding attrition; and • Killing the Red targets that are killing the most Blue platforms on the ground. COSAGE runs typically include both Blue and Red fixed-wing aircraft, but FATHM ignores these. This is because Blue aircraft are represented instead in the Air model, and Red aircraft are assumed to cause no attrition on account of the underlying assumption of , 1 1 pw w p t t p mxhours f hpd len mxplats + + ⇐ pw ∀
doi:10.5711/morj.12.4.33 fatcat:k2vffeymwvbmnf4guqbeugvyb4