A review was conducted of three systems analysis (SA) studies performed by Lockheed Idaho Technologies Company (LITCO) on integrated thermal treatment systems (ITTSs) and integrated nonthermal treatment systems (INTSs) for the remediation of mixed low-level waste (MLLW) stored throughout the U.S. Department of Energy (DOE) weapons complex. The review was performed by an independent team led by the Energy & Environmental Research Center (EERC), including Science Applications International Corporation, the Waste Policy Institute (WPI), and Virginia Tech. The three studies reviewed were as follows: (1) Integrated Thermal Treatment System Study, Phase 1 - issued July 1994, (2) Integrated Thermal Treatment System Study, Phase 2 - issued February 1996, and (3) Integrated Nonthermal Treatment System Study - drafted March 1996. The three studies were commissioned by DOE to be SA studies of environmental management (EM) systems. The purpose of LITCO`s engineering evaluation of the MLLW treatment system alternatives was to help DOE in the prioritization of research, development, and demonstration activities for remediation technologies. The review of these three studies was structured to further aid DOE in its current and future decision-making processes. The methodology in the studies was compared to a sound systems engineering (SE) approach to help DOE determine which tasks still need to be accomplished to complete a thorough design/review.