The Reset Structural Beam System tool recreates a beam system using the original beam system parameters. This tool can be used to undo changes to properties of individual beams in the system. After the beam system is reset, all beams in the system will have uniform parameters and be in the default locations. Specifically, the tool has the following reset effects:
Note that if the sketch of a beam system is modified, the beams of a system will remain attached to their original supports until the beam system is reset.

Original beam system

Beam system with changes
Using the Reset Structural Beam System tool
Mode panel
Edit Boundary.
Adjust panel
Reset System. 
Reset structural beam system
Mode panel
Finish Edit Mode. 
Beam system reset