Part Preparation
Before you assign constraints to a part, two preparation steps should be considered. The first is to check the part for inconsistencies that can interfere with constraint generation. The second is to select or restrict the portions of the part to work with.
The following buttons on the Parametric tab handle preparation tasks:
• 
Clean Pnt (in the Modify group)
Clean Pnt (in the Modify group)• 
Clean Duplicate (in the Modify group)
Clean Duplicate (in the Modify group)• 
Clean Stacked (in the Modify group)
Clean Stacked (in the Modify group)• 
Rigid (in the Create group)
Rigid (in the Create group)• Zone group buttons
• 
Zone (in the Show group)
Zone (in the Show group)