Tool Changing Cost per Edge
Tool changing cost = Tool changing time × (Machine operators' rate + Overhead)
Tool changing time is defined as the time required to remove the tool from the machine when it is worn out, to put new tool back into the machine, to reset the tool for size, and to get ready to start the machining.
In case of toolholders with indexable insert the tool change time would involve the time for indexing the inset and setting the tool for the dimension.