what is "observed PPM", "expected within PPM", and "expected overall PPM"?

drkstr747 — Fri, 14 Feb 2025 02:06:13 GMT

I was analyzing the process capability of a large data set to understand its PPM, and I noticed that under "nonconformance" tab, there are the following column names: Observed PPM, Expected Within PPM, and Expected Overall PPM.

What is the difference between these PPM?

Re: what is "observed PPM", "expected within PPM", and "expected overall PPM"?

jthi — Fri, 14 Feb 2025 05:19:56 GMT

Most likely those are same values as your Observed % but turned into PPM (parts per million). Usually you can use "?" tool from toolbar to figure out where to find the documentation but that doesn't always find the correct place, this seems to have best information I could quickly find from JMP help Example of Process Capability for a Stable Process

The estimates of out-of-specification product given in the Nonconformance report provide a direct measure of process performance. The PPM values in the Nonconformance report indicate that Gap hardly ever falls below the lower specification limit (1.4 parts per million). However, the number of parts for which Gap falls above the upper specification limit is 1869.0 parts per million.

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what is "observed PPM", "expected within PPM", and "expected overall PPM"?

Re: what is "observed PPM", "expected within PPM", and "expected overall PPM"?