Sains Malaysiana 54(9)(2025): 2327-2335

http://doi.org/10.17576/jsm-2025-5409-18

 

Monitoring Stability of Nonconformities Per Unit with Efficient Memory-Type Structure

(Memantau Kestabilan Ketakakuran Setiap Unit dengan Struktur Jenis Memori yang Cekap)

 

WAQAR HAFEEZ^1,*, ZAMEER ABBAS², HAFIZ ZAFAR NAZIR³ & SAJID SULTAN⁴

 

¹Haide College, Ocean University of China, Qingdao, Shandong, China
²KLATASDS-MOE, School of Statistics, East China Normal University, Shanghai, China
³Department of Statistics, University of Sargodha, Sargodha, Pakistan
⁴Dupty Director (Statistical Analyst), National School of Public Policy, Lahore, Pakistan

 

Received: 3 December 2024/Accepted: 2 July 2025

 

Abstract

For monitoring the qualitative characteristics of interest attribute control charts are recommended. Poisson control charts are most frequently used to track the number of nonconformities per unit in industrial processes during the inspection. This study introduces a Poisson EWMA (PEWMA) charting scheme using a progressive paradigm (PEWMA-p) to improve the sensitivity of the PEWMA chart for possible combinations of smoothing parameters. The proposed PEWMA-p chart has been developed for Poisson processes to monitor nonconformities per unit. The run-length (RL) profiles of the proposed PEWMA-p chart have been computed using extensively applied Monte Carlo simulations. The proposed PEWMA-p chart super-passes the counterparts for monitoring small shifts. An illustrative implementation related to the food quality for the proposed PEWMA-p with existing competitors is also part of the study which highlights the importance of the proposed chart.

 

Keywords: Attribute characteristics; control chart; EWMA chart; memory-type charting schemes; Poisson distribution

 

Abstrak

Untuk memantau ciri kualitatif minat, carta kawalan atribut disyorkan. Carta kawalan Poisson paling kerap digunakan untuk menjejaki bilangan ketidakpatuhan per unit dalam proses perindustrian semasa pemeriksaan. Penyelidikan ini memperkenalkan skema carta Poisson EWMA (PEWMA) menggunakan paradigma progresif (PEWMA-p) untuk meningkatkan sensitiviti carta PEWMA untuk kemungkinan gabungan parameter pelicin. Carta PEWMA-p yang dicadangkan telah dibangunkan untuk proses Poisson untuk memantau ketidakpatuhan setiap unit. Profil panjang larian (RL) carta PEWMA-p yang dicadangkan telah dikira menggunakan simulasi Monte Carlo yang digunakan secara meluas. Carta PEWMA-p yang dicadangkan melepasi rakan sejawat untuk memantau anjakan kecil. Pelaksanaan ilustrasi berkaitan kualiti makanan untuk PEWMA-p yang dicadangkan dengan pesaing sedia ada juga merupakan sebahagian daripada kajian yang menyerlahkan kepentingan carta yang dicadangkan.

 

Kata kunci: Atribut ciri; carta EWMA; carta kawalan; skim carta jenis ingatan; taburan Poisson

 

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*Corresponding author; email: waqarhafeez78601@gmail.com