Judul: Analisis Produk Cacat pada Agroindustri Ribbed Smoke Sheet dengan Pendekatan Lean Six Sigma dan Traceability.
Abstrak: Masih tingginya jumlah produk cacat menuntut PT X yang berlokasi di Bandung Barat, Jawa Barat untuk meningkatkan kualitasnya agar dapat tetap bersaing dan meningkatkan kepuasan konsumen terhadap produknya, salah satunya dengan Lean Six Sigma dan traceability yang berfungsi untuk meminimumkan jumlah produk cacat yang diproduksi. Penelitian ini bertujuan untuk mengidentifikasi penyebab terjadinya produk cacat dan memberikan solusi terhadap permasalahan. Tahapan penelitian menggunakan metode six sigma, yaitu define, measure, analyze, dan improve. Proses produksi pembuatan RSS terbagi menjadi beberapa tahapan, yaitu penyadapan, koagulasi, penggilingan, pengasapan, sortasi, dan penggudangan. Terdapat tiga critical to quality yang menyebabkan terjadinya produk cacat, yaitu gelembung, kotoran dan bagian tidak matang. Hasil pengukuran kinerja menggunakan nilai sigma menunjukkan PT X masih berada diatas rata-rata perusahaan di Indonesia, dengan nilai defect per million opportunity (DPMO) rata-rata 8997.46 dan nilai sigma rata-rata 3.95. Business process pembuatan RSS di PT X teridentifikasi beberapa stakeholder yaitu penyadap, mandor lapang, mandor pabrik, mandor pengolahan, mandor sortasi, pemasaran, head office, dan konsumen. Hasil analisis dengan fishbone diagram didapatkan penyebab terjadinya produk cacat yang teridentifikasi yaitu kurangnya konsentrasi dan ketelitian pekerja, kotoran pada bahan baku, suhu pengasapan, dan kendala alat yang digunakan selama proses berlangsung. Berdasarkan fishbone diagram, diperoleh saran perbaikan yang diajukan yaitu penambahan proses penyaringan saat penyadapan di kebun, perbaikan metode kerja, pengawasan kerja, pembagian jam kerja siang dan malam, dan maintenance serta penggantian suku cadang mesin secara rutin. Selain itu, penerapan gugus kendali mutu akan mempermudah perusahaan dalam melakukan perbaikan secara terus-menerus.
Keyword: Fishbone Diagram, Ribbed Smoke Sheet, Lean Six Sigma, Traceability

Judul: Analisis Pengurangan Jumlah Produk Cacat pada Industri Kertas dengan Pendekatan Lean Six Sigma
Abstrak: The high number of the defective product that occur in each company can affect quality. PT. X is a company engaged in the pulp and paper product. Lean approach does not allow for waste, in this case, defective product. Product defects that often arise in this industry are paper holes, dirty paper, folded, size variations and foreign contamination. The purpose of this study is to identify the causal factors in the production line of a product defect based on six sigma stages. The solution that can reduce the number of defects. The stages of six sigma are define, measure, analyze, improvement and control. The results of calculation of the value sigma of paper holes for two months was 4.66 and 4.58. Dirty paper has a sigma value of 4.99 and 5.06. The sigma level indicates that the performance of the production is above average Indonesian company. The costumer complaint coming into the company for folded paper, size variations and foreign contamination has decreased from 2010 to 2011. But it has not reached the six sigma target. Therefore, the company needs to be improved using the Lean tool, that is Kaizen Blitz.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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