Say you wish to update specification limits of some parameters of your manufacturing process searching for possibly more suitable limits. A way to find such limits is to calculate tolerance intervals (TI) for those parameters. A TI considers the proportion of future results to be within the limits range. Since future results are obviously unknown calculation also requires a predefined confidence level. Different combinations of confidence levels and proportions would result in different TIs.
A nice feature in JMP is the ability to add specification limits as a column property, which would use those for process capability analysis and show them on charts. However, a similar property for TI is missing. A way to compare specification limits and TI limits would be to manually add the TI limits to a chart so both would be shown on that chart. Doing so for a single parameter is reasonable but what if there are a dozen or two parameters to be explored. In such case, this may become tedious and time consuming, especially if wanting to explore different sets of TIs with several combinations of proportion and confidence level.
An ability to have TI as a column property, would allow for easy comparisons between set of limits. Currently in JMP it is possible to save the calculated TI as the specification limits but not having both intervals as separate column attributes since saving the TI as specification limits would delete any existing limits.
I have already opened a case for this request but would love to hear from other users about this suggestion, thanks.