Process

Model fit

A model of each machine predicts outcomes with a band. Its numbers are used only after four checks pass, including 90% intervals covering 85 to 95% of held-out points.

Model fit · Line A

Line model A a-2.2

Not accepted

90% interval coverage on 96 held-out points81%

70%85 to 95% accepted100%

Fail90% interval coverage81%, needs 85 to 95%
PassHeld-out error41 mPa·s
PassNo drift in residualsflat, 30 d
PassPhysical limits respectedall

Calibrated 17 Oct. Proposals on this line are withheld until all four checks pass.

Viscosity, last 30 runs

Held-out runs are compared with the model's band

Line A

Model fit · Line B

Line model B b-1.6

Accepted

90% interval coverage on 214 held-out points91%

70%85 to 95% accepted100%

PassHeld-out error0.21 % scrap
Pass90% interval coverage91%
PassNo drift in residualsflat, 30 d
PassPhysical limits respectedall

Calibrated 12 Oct. Proposals on this line may carry a number.

Scrap rate, last 30 runs

Held-out runs are compared with the model's band

Line B

Withheld because of fit

1 proposal

Process agent·Line A·Jacket loop·Hold temperature 84 to 88 °C·08:00Recommend-onlyWithheld

Hold temperature: no number offered

Model of the mixer is outside its accepted fit for the new grade A-14, so no number is offered.

EV-A-1201

If stoppedNothing was written.

NoticedProposedWithheld

What a failed check changes

While a model is not accepted, its line can still be watched and recommended to, but proposals carry no number and nothing is written. The process engineer sees the failing check first and can re-run the fit after recalibration.