Motion skeletons are available in Assembly, allowing motion to be incorporated into the model at the beginning of the design process. There is no longer a need to recreate an assembly to include a mechanism analysis. User can create mechanism bodies and connections as a motion skeleton, then run a simple kinematic analysis to ensure that the skeleton provides the appropriate degrees of freedom. User can then create and assemble components to the motion skeleton. Motion skeletons are defined in the same way as normal assembly skeletons and include reference control settings. They do not appear in the assembly bill of materials.