There is a tactical advantage to war-game modeling: using maps, figurines, virtual reality and full-scale exercises allow warfighters to “see” a battle beforehand and prepare for the challenges they will face. Virtual sand tables are making that even easier, showing terrain and building representations in an easy-to-use format.

Modeling and simulation can also be used to develop new technology. How a new technology will perform can be tested both virtually and in the lab. For example, a new aircraft wing shape can be drawn on a computer and then tested in a wind tunnel. Both sets of tests are a form of modeling.

Additionally, new technologies can be tested and evaluated for human compatibility. Ultimately, the end user must be able to understand the system and be able to interact with it in a comfortable manner, both physically and intellectually. Labs such as the Usability Lab run by the National Center for Telehealth and Technology  are great examples of this type of simulation.

Sources:
http://www.au.af.mil/au/awc/awcgate/awc-sims.htm
http://www.afams.af.mil/index.asp
http://www.ms.army.mil/
http://www.dod-msiac.org/
http://science.dodlive.mil/2011/05/11/modeling-human-interface/
http://science.dodlive.mil/2011/11/02/is-it-user-friendly-this-new-lab-will-find-out/

Credit: http://science.dodlive.mil/2011/11/11/ten-technologies-a-brief-look-at-military-evolution-modeling-and-simulation/