The computer software AUSSSM TOOL, originating from the methodology of the revised-architectural-urban-soil-simultaneous simulation model (revised-AUSSSM), was developed by adopting the graphical user interface (GUI) features to support users, who can use the interactive computer display for parameter settings, simulating, visualizing, and reporting the numerical calculation results instead of complicated programming. The purpose of the AUSSSM TOOL is to determine quantitative parameters such as air temperature, exhaustive heat from air conditioning systems, energy heat balance, etc. within the urban canopy structure, which data enables the evaluation of effects of urban heat island (UHI) in concrete terms useful to urban planners, architects, engineers, and so forth in the field of urban climatology involving building scale. In addition to conducting a full numerical simulation, in order to simplify a comparison among complex factors influencing UHI, numerical experiments based on Taguchi design of experiment theory (DOE) were carried out. The results of the numerical experiments were stored in a database and ready to be instantly grasped by any inexperienced user corresponding to their specified conditions. This paper describes the fundamental method of the revised-AUSSSM, the objectives of related software development, and the structures of the AUSSSM TOOL and the techniques comprising its algorithm to present the numerical simulation results in particular.