There are many papers on the applicability of certain trend rules for dispersion charts.
If you are not comfortable with JSL, create a table of the moving range of means, then use the control chart builder for an Individual chart or a Levey-Jennings chart then select the trend rules recommended for a moving range.
From experience, many who look at a moving range don't realize if there is a shift in the mean that persists, only 1 OOC point, at the point of the shift, will appear on teh control chart. Also, if one mean is unusual then you will get 2 unusual range points: 3 menas that are typical, unusual, typical, the two moving ranges involving the OOC will be unusual. So I understand why JMP does not automatically supply trend rules. However, the trend rule that flags too many points close to the center line, demonstrates a reduction in variability and a trend rule with 10-15 points not within the zones closest to the center line demonstrates an increase in variability ( worse stability).
http://metal2012.tanger.cz/files/proceedings/02/reports/402.pdf