It is also possible to direct modeling the model, when the history of operations is unavailable. (This is the case for 3d STEP models). Defeaturing can also useful to remove proprietary details of the model before sharing it.
See also Defeaturing
There are also tools to create more solid shapes, from edges, faces or shells.
These defeaturing and repairing tools work with FreeCAD 0.15, 0.16, 0.17 and 0.18. More advance defeaturing tools can be used if OCC7.3 are available.
- Author: Github: @easyw | FreeCAD Forums: 
- Source code on github: https://github.com/easyw/Defeaturing_WB
- FC forum thread https://forum.freecadweb.org/viewtopic.php?style=3&f=9&t=29506
The Defeaturing Tools are located in a separate mask.
These are in particular:
- Remove Holes: remove Hole from Face
- Remove listed Faces: remove 'in List' Faces
- Add Faces from 'in List' Edges: add Faces from 'in List' Edges
- Select Faces to be Parametric defeatured: select Faces to be Parametric defeatured
- Create a copy of the 'in List' Edges : create a copy of the 'in List' Edges
- copy Faces from 'in List' Faces : copy Faces from 'in List' Faces
- offset face: offset face
- offset edge: offset edge
- Make Solid from in List Faces: make Solid from in List Faces
- Make Solid from the Faces of the selected Objects: make Solid from the Faces of the selected Objects
- Make Solid from in List Faces: select ONE object to try to make a Solid through STEP import/export process
- Connect: connect
- clean Face(s) removing holes and merging Outwire: clean Face(s) removing holes and merging Outwire
- show 'in List‘ Edge(s): show 'in List‘ Edge(s)
- show 'in List‘ Face(s): show 'in List‘ Face(s)
- refine: refine
- simple copy: simple copy
- parametric Refine: parametric Refine
- geometry check: geometry check
- get Tolerance value: get Tolerance value
- set Tolerance value: set Tolerance value
- make Edge from selected Vertexes: make Edge from selected Vertexes
- reset Placement: reset Placement
- show/hide TypeId of the Shape: show/hide Type Id of the Shape
- help: help
Removing Features using OCC7.3 new tools
- Sew a Shape
- Removing or Simplify Faces
- Remove Holes or Pockets
- Read or Change Tolerance
- make Fuzzy Boolean operations
- automatically using the FreeCAD Add-on Manager (bundled in to 0.17 dev version under Tools Menu)
- manually by copying the Manipulator folder to the Mod sub-directory of the FreeCAD application.
- FreeCAD v0.15 4671
- FreeCAD v0.16 >= 6712
- FreeCAD v0.17 >= 13522
- FreeCAD v0.18
FreeCAD workbenches are easy to program in Python, there are therefore many people developing additional workbenches outside of the FreeCAD main developers.
New workbenches are in development, stay tuned!