Severe trauma injuries create major challenges for military medical personnel treating casualties at the point of injury. Many trained medical personnel are not psychologically prepared to face severe wartime traumatic injuries. The U.S. Army Research Laboratory, Human Research and Engineering Directorate, Simulation and Training Technology Center (ARL-HRED STTC) under the severe trauma initiative developed innovative technologies to realistically simulate the look, feel and smell of severe trauma to prepare medics, combat lifesavers and Soldiers to deal with the injuries encountered on the battlefield. The Multiple Amputation Trauma Trainer (MATT®) developed under this initiative is a high-fidelity Improvised Explosive Device (IED) blast injury simulator with state-of-the-art special effects, sensing and animatronics technologies to support hemorrhage control training. This simulator introduced movement for the first time, increasing realism and immersion to support stress inoculation training. Further development led to a high-fidelity Hemostatic Agent Trainer to support learning how to address non-extremity wounds and stem the flow of blood in such an injury. A prototype upper body trainer was also developed, including a face capable of simulating expressions in response to pain, as well as support for a variety of medical procedure training including needle decompression and airway management. This paper will discuss in detail how training requirements and the student's need to master a variety of procedural skills impacted the design of the MATT®. It will also look at the criteria used to develop the overall design and identify specific capabilities. In addition, it will discuss how subject matter expertise was utilized to develop requirements, metrics and processes used to evaluate the overall benefits of the program. Finally, it will discuss results from usability evaluations and lessons learned from the development and implementation of this project.