Passing Control Limits into SPC Charts - Part 2
I'm able to pass control limits (LCL, CL, UCL) into my SPC chart but it's not woking quite as I expected. If I look at the raw data detail, I see:
Date Prod LCL Mean UCL
Oct-2005 298265 100000 150000 200000
Feb-2006 298171 120000 150000 160000
Aug-2006 198144 75000 125000 175000
Mar-2007 2144 40000 100000 160000
Aug-2007 144 40000 100000 160000
I would have assumed that the LCL, Mean, UCL from the first row (100000, 150000, 200000) would "take effect" on that row's date (10/2005) and continue for all FUTURE data points until the first subsequent date that had a different LCL, Mean, UCL value(s) but, looking at the SPC chart, it seems whenever there is a change in the LCL, Mean, UCL, the values apply to data points PREVIOUS to that row's date.
I'd like users to enter LCL, Mean and UCL data into a control limits database whenever there is a change in the values that should be applied to future points but I don't think that's the way the SPCChart template works.