A different Xbar/R chart

Usually the Xbar/R charts you can find in the marketplace run on specific software (not for free) and they tend to be more complicated than what you really need. You mostly find Xbar/R charts that develop horizontally rather than vertically.

The following examples show the Xbar/R charts that are commonly found and used:

The tool I present here takes all the advantages of Excel vertical filter function and creates charts that can extend “for ever” downward.... (3 measures a day means more than 1,000 years).

This means that you don’t have to scroll horizontally the chart to find your current data; instead, you can use the faster page-down / page-up buttons or macros that use row numbers as iteration variables.

The chart I free-share here works downward, as explained here below: the first column hosts day, time and shift who took the measurements. The tool shows the Spec limits (in red, LSL and USL) and the control limits (in purple, LCL and UCL) for the «average) »; of course, only the control limits for the «R (range)»

This chart works on 3 data points (but it can be extended) and it shows right away (the cell turns red) when the value is out-of-spec. This is useful when some data points fall out of spec, but the average is within tolerance (visible in the picture above).

On the right side of the screen, a column to display the cpk is available; it is flexible, so the user can grab the 25 triplets from the data input columns and paste them straight into the «cpk» sheet for immediate evaluation.

For example, to evaluate the cpk (0.62) of the first 25 data groups, the procedure is the following:

The program is totally free. You can grab and use. 👍

EffBee

Xbar_Range__Process_1_EffBee

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