In this study a computer program was developed using Visual Basic and Visual LISP programming languages to comprehensively analyze the strength, deformation, vibration, manufacturing, and drawing of a rotating circular stepped shaft. These shafts have a variety of power transmitting mechanical elements (components), such as pairs of gears, and pulleys that are modeled in 31). in addition, force and moment analyses of these elements running on the shafts were examined. Notch sensitivity and stress concentration factors given graphically were formulated using the finite difference method. Vibration analysis was also included to the software. Furthermore, to select the best rolling-contact bearings, an expert system requiring the knowledge-based technique was employed. The user is given the choice of shaft material and other parameters. After saving the data regarding calculated and designed shaft, these,data are transferred to the graphical environment for detail drawing and CNC code generation of the shaft. A program, which is called shaft and gear design program, has been developed for this process. (C) 2007 Wiley Periodicals, Inc.