“…Chart in design can be called design tolerance chart (DTC), and chart in process planning can be called process tolerance chart (PTC). The latter has been covered in various literature since the 1950s (Gadzala 1959, Wade 1967, Nicks 1982, Wade 1983, Curtis 1988, Ahluwalia and Karolin 1986, Fainguelernt et al 1986, Irani et al 1989, Whybrew et al 1990, Mittal et al 1990, Abdou et al 1993, Ji 1993, 1995, Ngoi et al 1993, 1994, Britton et al 1997, Krag 1997. Those references, from US sources as well as from outside USA, are not a complete list; but they are the major ones in the subject area.…”