Cable skyline systems are often used to yard felled trees in mountain forests. As they are in the difficult terrain forest stands and these operations are process of the works by temporal setting at the irregular shape site, it has been difficult to be standardized and to store results useful for the following operations. Pre-processes for the operation are inevitable such as for design of process management and for mechanism rig up of the operation and usually their simplification is expected, and always the craftsmanship of the operation staff is required. The recent development of high-definition local environmental information and the ease of public use made it easy for them to be made possible in a short period of time. Furthermore, the simulation method using CG technology makes it possible to examine various location relationship, mechanisms, etc. of real three-dimensional space by VR etc. Here I show 1) modeling the main rigging method that has been used so far in a digital three-dimensional space on a PC, 2) cable rigging can be designed quickly, one day for a yarding site, 3) validating and revising smooth yarding operation, by virtual yarding operation with keyboard/joystick control for design better setting and operation, 4) designing and creation of data system for storing the results of the operation to improve following operations, which may support timber SCM. Moreover, it can be applied to develop a new cable skyline mechanism.