Sains Malaysiana 50(12)(2021): 3733-3744

http://doi.org/10.17576/jsm-2021-5012-22

Optimised Reduction of Surgical Gloves Pinholes using Forward Search Method

(Penurunan Teroptimum Lubang Jarum pada Sarung Tangan Pembedahan menggunakan Kaedah Pencarian Terkehadapan)

AZIMAH AHMAD¹, NUR ANISAH MOHAMED @ A. RAHMAN¹* & ZAHARAH WAHID²

¹Institute of Mathematical Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Federal Territory, Malaysia

²Kulliyyah of Engineering, International Islamic University Malaysia, 53100 Gombak, Selangor Darul Ehsan, Malaysia

Received: 18 September 2020/Accepted: 6 April 2021

ABSTRACT

This research investigates the factors that affect the existence of pinholes in surgical gloves during the manufacturing process. Since eight factors affect the existence of pinholes in surgical gloves, a two-level fractional factorial design 2^8-4 was used to study the main effects and the first-order interactions of the multiple variables. Multiple linear regressions are used to model the data. This paper also examines the presence of influential points in the data using the influential measures in linear regression such as Cook’s Distance, DFFITS, DFBETAS, Studentized Residual, Standardized Residual, Hadi's measure, and the robust forward search. The impact of influential points is further assessed through deletion of potential influential points and model selection using adjusted R2, information criterion, and stepwise selection to see whether these influential points significantly improved the existing model. 

Keywords: Fractional factorial design; influential points; multiple linear regression; robust forward search; stepwise selection

ABSTRAK

Kertas penyelidikan ini mengkaji faktor-faktor ketika proses pembuatan yang menyebabkan kewujudan liang jarum pada sarung tangan pembedahan. Oleh kerana terdapat lapan faktor yang menyebabkan kewujudan liang jarum pada sarung tangan pembedahan, reka bentuk dua-peringkat faktorial pecahan 2^8-4 digunakan untuk mengkaji kesan-kesan utama dan interaksi peringkat pertama pelbagai pemboleh ubah ini. Regresi linear berganda dengan terma interaksi digunakan untuk memodelkan data. Kertas penyelidikan ini turut mengkaji kewujudan titik-titik berpengaruh dalam data dengan menggunakan ukuran berpengaruh dalam regresi linear seperti Jarak Cook, DFFITS, DFBETAS, reja piawai, reja studentized, Ukuran Hadi dan aturan Pencarian Kedepan yang mantap. Impak titik-titik berpengaruh ini terus dinilai melalui penghapusan titik-titik berpengaruh yang berpotensi dan pemilihan model menggunakan R² yang disesuaikan, kriteria informasi dan pemilihan bertahap untuk melihat sama ada titik-titik berpengaruh dapat meningkatkan model sedia ada dengan ketara.

Kata kunci: Pemilihan bertahap; pencarian kedepan mantap; reka bentuk faktorial pecahan; regresi linear berganda; titik-titik berpengaruh

REFERENCES

Atkinson, A.C. & Riani, M. 2000. Robust Diagnostic Regression Analysis. New York: Springer Science & Business Media.

Atkinson, A.C., Riani, M. & Cerioli, A. 2012. Problems and challenges in the analysis of complex data: Static and dynamic approaches. In Advanced Statistical Methods for the Analysis of Large Data-Sets, edited by Di Ciaccio, A., Coli, M. & Angulo Ibanez, J.M. Berlin, Heidelberg: Springer-Verlag. pp. 145-157.

Azur, M.J., Stuart, E.A., Frangakis, C. & Leaf, P.J. 2011. Multiple imputations by chained equations: What is it and how does it work? International Journal of Methods in Psychiatric Research 20(1): 40-49.

Belsley, D.A., Kuh, E. & Welsch, R. 1980. Regression Diagnostics: Identifying Influential Data and Sources of Collinearity. New York: John Wiley & Sons.

Cook, R.D. 1977. Detection of influential observation in linear regression. Technometrics 19(1): 15-18.

Gaffert, P., Meinfelder, F. & Bosch, V. 2016. https://www.uni-bamberg.de/fileadmin/uni/fakultaeten/sowi_lehrstuehle/statistik/Personen/Dateien_Florian/properPMM.pdf. Towards and MI-proper predictive mean matching.

Gessler, A., Stärk, A., Sigwarth, V. & Moirandat, C. 2011. How risky are pinholes in gloves? A rational appeal for the integrity of gloves for isolators. PDA Journal of Pharmaceutical Science and Technology 65(3): 227-241.

Hadi, A.S. 1992. A new measure of overall potential influence in linear regression. Computational Statistics & Data Analysis 14(1): 1-27.

Jirasukprasert, P., Garza-Reyes, J.A., Kumar, V. & Lim, M.K. 2014. A six sigma and DMAIC application for the reduction of defects in a rubber gloves manufacturing process. International Journal of Lean Six Sigma 5(1): 2-21.

Lüdtke, O., Robitzsch, A. & Grund, S. 2017. Multiple imputation of missing data in multilevel designs: A comparison of different strategies. Psychological Methods 22(1): 141-165.

Malaysian Rubber Export Promotion Council (MREPC). 2020a. Malaysia's Exports of Selected Rubber Products. http://www.mrepc.com/industry/malaysia_export.php.

Malaysian Rubber Export Promotion Council (MREPC). 2020b. Standard Malaysian Glove: Product Specifications. http://www.smgonline.biz/products_specifications.html.

Montgomery, D.C. 2009. Introduction to Statistical Quality Control. 6th Ed. New York: John Wiley & Sons.

Oehlert, G.W. 2000. A First Course in Design and Analysis of Experiments. New York: Freeman & Company.

Ong, E.L., Lai, P.F., Lim, C.L. & Ng, K.P. 2001. Standard Malaysian Glove Scheme: Technical Requirements. Asian Gloves and Dipped Goods Directory, Rubber Asia Publication. p. 59.

Patel, H., Fleming, G. & Trevor Burke, F. 2003. A preliminary report on the incidence of pre-existing pinhole defects in nitrile dental gloves. British Dental Journal 195(9): 509-512.

Schafer, J.L. & Graham, J.W. 2002. Missing data: Our view of the state of the art. Psychological Methods 7(2): 147-177. 

Siddique, J. & Belin, T. 2008. Multiple imputation using an iterative hot-deck with distance-based donor selection. Statistics in Medicine 27(1): 83-102.

Tan, A.H., Cham, C.L. & Lim, E.H.Y. 2020. Analysis and prediction of glove quality based on manufacturing factors. In 2020 IEEE International Conference on Power and Energy (PECon). IEEE. pp. 420-425.

Wahid, Z. 1998. Potential for process improvement of the rubber glove manufacturing industrial case study process: An industry case study. University of Newcastle. Ph.D. Thesis (Unpublished).

Wahid, Z. & Tham, M.T. 2012. Single array and response modeling of robust design experiments. International Journal of Applied Physics and Mathematics 2(5): 359-361.

*Corresponding author; email: nuranisah_mohamed@um.edu.my