does this only work in the latest version of JMP? I am still using JMP 8 and the "Show as graph reference lines" option doesn't appear. To get spec lines to appear on a Box Plot (for example), I have resorted to the ugly method of parsing the output of Get Property("spec limits")! I am sure there is a nicer way to do it even in JMP8, can you help me out? It happens automatically in a Distribution plot, but not a box plot or variability chart.
My licence for JMP 8 seems to have expired so unfortunately I can't easily test if and how it could work in that version. However "Show as graph reference lines" is there as an option in both JMP 9 and 10.