Читать книгу Simulation and Wargaming - Группа авторов - Страница 34

Many, if not most, of today’s computer‐based combat simulations are extraordinarily complex (the Concepts Evaluation Model, a theater‐level deterministic closed‐loop combat simulation used by the US Army’s Concepts Analysis Agency in the late twentieth century was over 250 000 lines of computer code). However, that complexity does not translate into a model that can accurately predict the outcome of combat. This complexity has given rise to two different schools of thought. Simulation skeptics refer to them as “black boxes,” which means that the users of these simulations have little to no understanding of the simulation’s processes that convert inputs into outputs. Some simulation advocates believe that with the complexity that these simulations have, all the processes of combat are modeled to a high degree of precision, thus the simulation’s outputs must be believed without question or debate. Subscribers to either school miss the fundamental truth that the models in these simulations are abstractions and approximations of some specific aspects of combat that the simulation was originally designed to model. All simulations are comprised of one or more models, and all models are an abstraction of reality, with some processes modeled explicitly, some implicitly, and some processes not modeled at all because the simulation’s designer did not intend for the simulation to address those excluded processes. Prospective simulation users need to do some research and come to at least a basic understanding of what a simulation under consideration for use in a particular study was originally designed to model, and what its strengths and shortcomings are before they select a simulation that will be useful for the purpose at hand. In a RAND paper examining non‐monotonic, chaotic output from a very simple deterministic, Lanchester‐based combat simulation (2 variables, 18 data elements, and 8 rules), the authors state “The typical model simulates combat between opposing forces at some level of abstraction. No combat model is seriously expected to be absolutely predictive of actual combat outcomes. It is common, however, to expect models to be relatively predictive. That is, if a capability is added to one side and the battle is refought, the difference in battle outcomes is expected to reflect the contribution of the added capability.”³² This concept of relative predictability underpins the usage of simulations to conduct Analyses of Alternatives, or AoAs, studies that are used to justify weapon system acquisitions in DoD.