The lookup table tblGtolProcessCapabilities lists the geometric tolerance grade and roughness ranges achievable by a given process for a given type of tolerance/roughness. A tolerance grade range together with a feature size determines a literal tolerance range. See the section “How aPriori calculates achievable tolerance ranges” in the aPriori Professional User Guide.

In addition to affecting cycle times of secondary machining operations, the ranges affect what operations are listed as tolerance-driven machining operations and what operations are listed as special finishing operations. See the Tolerances and Finishing Operations section of the Design to Cost tab.