what is the procedure for doing a Multivariace Control Chart?
How practical is it to implement on the production floor where it can be useful to the operator?
If you really mean a "Multivariate" control chart in JMP, from the JMP main menu bar select Analyze -> Quality and Process -> Control Chart -> Multivariate Control Chart. Populate the Y, Columns window with the appropriate variables for consideration, with options for subgrouping, or if in Phase II, getting target values from the Phase I process characterization steps. Select OK, when finished with selections. See the example window below:
You can find additional details here in the JMP online documentation:
Practicality of implementing a control chart strategy on a shop floor is going to be totally dependent on the willingness and effort expended by leadership on incorporating sound process monitoring thinking within the hearts and souls of all those who work with the process. It's not a statistical methods question but a question of leadership. If company leadership is unwilling to invest in supporting fully the rational use of these methods...then no amount of statistics horsepower is going to overcome this lack of leadership support.