The U.S. Army Research Development and Engineering Command Simulation and Training Technology Center (RDECOM-STTC) was challenged to develop a low cost, lightweight and low power system for dismounted soldiers to use for mission planning and rehearsals. The Team Mission Assistant-Tactical/Exercise (TeamMATE) device was developed by the Scalable Embedded Training and Mission Rehearsal (SET-MR) Army Technology Objective (ATO) to meet this challenge. The TeamMATE was developed on a Personal Digital Assistant (PDA) and designed to support four modes: Plan, Rehearse, Execute, and Review. A heuristic evaluation was performed on the TeamMATE user interface by the Army Research Laboratory to test its usability and effectiveness. The TeamMATE was also evaluated by dismounted soldiers at the Joint Readiness Training Center at Fort Polk, Louisiana for its usability. The TeamMATE was later demonstrated to the Future Warrior Technology Integration (FWTI) program at Natick Soldier Center in Natick, MA. The capabilities of the TeamMATE were desired, but the form factor had to meet the FWTI system requirements. Using the previous evaluations, the SET-MR ATO team re-engineered the TeamMATE only keeping the core capabilities for the FWTI Team. A new simulation system was then developed to meet the FWTI requirements. The system was entitled Soldier Training Enhancement Package (STEP). The previous evaluations also prompted the RDECOM-STTC team to start a Small Business Innovative Research (SBIR) project to potentially provide advanced capabilities to the FWTI system. The project goal was to develop advanced technologies that the soldiers had identified as critical needs. The team has since identified some off-the-shelf technologies that were readily available to meet the identified critical needs and have since adapted that technology for use. This paper analyzes the results from the studies performed and discusses how those studies have helped in the design and development of the mobile, hand-held devices technologies being used today.