English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

When a high-quality process is to be controlled by 100% inspection and yes-no decision isemployed, several types of charts come into account, e.g. CCC, CCC-r or geometric CUSUM(CCC-CUSUM). The aim of the paper is to examine performance of these charts so that a suitableone can be chosen for a given process. The charts are compared according to the quickness withwhich the upward shift in the fraction of nonconforming items is detected. The average numberof observations to signal (ANOS) instead of the usual average run length (ARL) is determined.While ANOS for CCC or CCC-r charts can be easily calculated based on a geometric or a negativebinomial distribution, its computation is quite diffi cult in the case of CCC-CUSUM chart. Thecorrected diffusion (CD) approximation was used to determine ANOS and the results were verifi edby Monte Carlo simulation. Zero-state and steady-state (both fi xed-shift and random-shift model)analyses were performed to take different scenarios of the process shift occurrence into account.CCC-3 or CCC-2 and CCC-CUSUM charts were compared. The order r for CCC-r chart waschosen as an optimal value for the given process based on the semi-economic model suggested inBrodecka (2013). Our study revealed that for in-control p0 equal to 0.0002 the CCC-CUSUM chartperforms best especially for shifts around the pre-specifi ed out-of-control fraction nonconforming.The CCC-r chart may be comparable or even better in detecting larger shifts. The results of thecomparative study were utilized for the choice of the most suitable and best performing control chartto control the high-yield process producing ERG (Exhaust Gas Recirculation) sensors. Comparisonsof CCC-r and CCC-CUSUM charts can be found elsewhere in literature, but conclusions seem tobe rather inconsistent. To our best knowledge no study dealing with such small in-control fractionnonconforming together with the low risk of false alarm has been published yet. The choice ofCUSUM’s parameters and consequent values of ANOS can help practitioners who need to controlhigh-quality processes.

Comparative Statistical Analysis of Selected Control Charts for Highly Capable Processes