Diagram Kendali Grup Runs untuk Mendeteksi Pergeseran dalam Rata-Rata Proses

Handi Firli Pratama, Suwanda Suwanda

Abstract


Abstract. The control chart used to check for large changes in the average effective process above 2σ is the Shewhart control chart ( ), but the Shewhart control chart is less sensitive or performs poorly in detecting small or moderate changes. To detect small changes below 1σ can use CUSUM (Cumulative Sum)  and EWMA (Exponentially Weighted Moving Average), but these two diagrams are not yet popular in practice. Wu and Spedding [12] have proposed a synthetic control chart for detecting small shifts in the process mean. For the same problem we propose a control chart called a 'Group Runs' (GR) control chart which is a combination of a Shewhart control chart and an extended version of the CRL (Conforming Run Length) chart. Average Time to Signal (ATS) on the GR control chart will be compared with the Shewhart control chart and Synthetic control chart

Keywords: Average Time To signal, Conforming Run Length Chart, Synthetic Chart,  Chart

Abstrak. Diagram kendali yang digunakan untuk mendeteksi perubahan besar dalam  rata-rata proses secara efektif diatas 2σ yaitu diagram kendali Shewhart ( ), namun diagram kendali Shewhart kurang sensitif atau kinerjanya buruk dalam mendeteksi perubahan kecil atau sedang. Untuk mendeteksi perubahan kecil dibawah 1σ dapat menggunakan diagram CUSUM (Cumulative Sum) dan EWMA (Exponentially Weighted Moving Average), namun kedua diagram ini belum popular dalam praktiknya. Wu dan Spedding[12] telah mengusulkan diagram kendali sintetis untuk mendeteksi pergeseran kecil dalam rata-rata proses. Untuk masalah yang sama kami mengusulkan diagram kendali yang disebut diagram kendali ‘Grup Runs’ (GR) yang merupakan kombinasi antara diagram kendali Shewhart dan diagram CRL (Conforming Run Length) versi diperpanjang. Aplikasi diagram kendali Grup Runs diterapkan pada data kecepatan pelayanan di BPS DKI Jakarta yang merupakan hasil penelitian Salam dan Suwanda (2009).

Kata Kunci: Diagram Kendali Sintetis, Diagram Kendali , Rata-Rata Waktu Sinyal, Penyesuaian Panjang Lari,


Keywords


Diagram Kendali , Conforming Run Length (CRL), Diagram Kendali Sintetis, Average Time to Signal (ATS).

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References


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Wu, Z. and Spedding, T. A. (2000). A Synthetic Control Chart for Detecting Small Shifts in the Process Mean. Journal of Technology 32, 32-38




DOI: http://dx.doi.org/10.29313/.v7i1.25377

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