Judul: Aplikasi Multivariate Exponentially Weighted Moving Average dalam Pengendalian Kualitas Produksi Billet Baja
Abstrak: Baja adalah salah satu jenis logam dengan peranan penting dalam kehidupan manusia, khususnya untuk konstruksi. Indonesia sendiri merupakan eksportir baja terbesar kesepuluh di dunia dengan pangsa pasar 3,37%. PT Jakarta Cakratunggal Steel Mills sebagai salah satu produsen baja terkemuka di Indonesia juga turut berkontribusi dengan menghasilkan baja tulangan beton (billet). Billet baja terbanyak yang diproduksi oleh PT Jakarta Cakratunggal Steel Mills pada tahun 2021 adalah jenis CS42 dengan total 432 kali produksi. Tingginya angka produksi CS42 tersebut menjadikan pengendalian kualitas produksi billet baja menjadi fokus perhatian. Multivariate Exponentially Weighted Moving Average (MEWMA) memiliki kemampuan untuk mendeteksi perubahan kecil terhadap rata-rata proses multivariat, sehingga menjadikannya sebagai bagan kendali yang sensitif terhadap pergeseran rata-rata dalam proses produksi. Kemampuannya diukur dengan menerapkan Average Run Length (ARL) dan nilai pembobot (λ) optimum untuk mendeteksi sinyal out-of-control. Penelitian ini bertujuan untuk menganalisis proses kontrol produksi billet baja CS42 dengan menggunakan bagan kendali MEWMA, menguji kapabilitas prosesnya, dan mengidentifikasi unsur kimia dominan yang potensial menjadi peubah tak terkendali. Hasil penelitian ini menunjukkan bahwa pengaplikasikan bagan kendali MEWMA dengan nilai λopt = 0,2 dan ARL = 200 memberikan hasil bahwa proses produksi billet baja CS42 Jakarta Cakratunggal Steel Mills pada tahun 2021 belum terkendali secara statistik. Indeks Kapabilitas proses Billet baja CS42 memiliki nilai kapabilitas proses yang kurang baik karena nilainya sebesar 0,4533 masih di bawah ketentuan sebesar 1,33. Unsur kimia Mangan (Mn) teridentifikasi sebagai unsur kimia yang berkontribusi paling besar sebagai penyebab terjadinya out-of-control saat produksi billet baja., Steel is one type of metal with an essential role in human life. Indonesia globally evidenced a high demand for steel in the tenth position as the world’s largest steel exporter, with a market share of 3.37%. PT Jakarta Cakratunggal Steel Mills is one of Indonesia’s leading steel producers that fabricate reinforced concrete (billet) and likewise contribute to this. The highest steel billets produced by the company throughout 2021 were the CS42, with 432 times. This number makes quality control of steel billet production a topic in the spotlight. The Multivariate Exponentially Weighted Moving Average (MEWMA) can detect minor changes in the multivariate process average, increasing shift-sensitive control. Its performance was measured by applying the Average Run Length (ARL) and the optimum weighting value (λ) to detect out-of-control signals. This study aims to analyze the process control of CS42 steel billet by applying MEWMA, comprehending the process capability, and identifying the dominant chemical element that has the potential to become an uncontrollable variable. The results indicate that MEWMA possesses the detecting ability to detect out-of-control signals compared to other control charts. CS42 steel billets have a modest capability value because they are below 1.33, which is 0.4533. Manganese (Mn) is the most out-of-control chemical element during steel billet production.
Keyword: Multivariate Exponentially Weighted Moving Average (MEWMA), Quality control, Steel billets

Judul: Pengendalian Proses Baja Karbon Tinggi di Pabrik Billet Baja PT Krakatau Steel (Persero) Tbk, Cilegon
Abstrak: Process control is used to guarantee a product/service that was produced to meet certain specification and has high uniformity over time. Process control generally uses quality control charts that is used to detect the causes of high variability a product. Quality control charts that was used in this study was Generalized Variance control chart and Individual Hotelling T2 control chart. The Individual Hotelling T2 control chart was done after the Generalized Variance control chart was under control. Based on the results of the Generalized Variance (GV) control chart and the Hotelling T2 control chart using a confidence level of 99.73%, the process of high carbon steel was under control after observations that were outside the control limits were removed, which means variance and average of the process was under control. However, the identification of the previously uncontrolled observations was done first. One way to determine the variables (elements) that affected the out of control observation was to calculate the decomposition value of out of control observations. Based on these values, it indicated that the variables mainly causes out of control observation were Cu, Ni, S, and P.
Keyword: Generalized Variance control chart, Individual Hotelling T2 control chart, out of control observation

Judul: Kampung Halaman dalam Perspektif Sosiobudaya
Abstrak: Kampung halaman adalah daerah asal atau daerah tempat kelahiran seseorang. Manusia terikat dengan kampung halamannya secara fisik dan sosiobudaya. Keterkaitan manusia dengan kampung halaman ini mengakibatkan manusia tidak mau berpisah dengan kampung halamannya sampai akhir hayat.
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