You must have defined a rough stock in the part operation. A rough stock that is defined in the part operation before starting the definition of the manufacturing program will be used for all of the successive machining operations, each working on the residual material left by the machining operation before it.
You must have computed at least one machining operation prior to this one in the manufacturing program.
The rough stock used for a manufacturing program where you insert a reworking operation must be topologically closed, that is, it cannot be formed by a set of faces.
Roughing rework does not function correctly if you have a rough stock in several parts because the rework rough stock will be defined as the containment box around them.
Optional:
modify any parameter other than the ones described below in the dialog box.