Judul: Evaluasi Variabilitas Bobot Bersih Mie Snack Gorengan pada Proses Packing Vertikal di PT XYZ
Abstrak: Mie Snack merupakan pangan olahan berbahan dasar tepung terigu yang pengolahannya menggunakan proses penggorengan. Seiring dengan tingginya permintaan produk mie snack dari konsumen, diperlukan upaya dari PT. XYZ untuk meningkatkan jumlah produksi dan menekan jumlah broken produk karena variasi bobot produk. Tujuan penelitian ini adalah mengidentifikasi dan menganalisa faktor penyebab variasi bobot bersih mie snack gorengan di PT. XYZ serta menghitung nilai Cp (Capability process) dan nilai Cpk (Index capability process) dari proses pengemasan pada mesin packing vertikal. Penelitian ini menggunakan metode PDCA (Plan, Do, Check, Action) dengan alat bantu diagram Ishikawa dan control chart dari seven tools. Hasil penelitian menunjukkan bahwa penyebab variasi bobot produk berasal dari faktor mesin, yang merupakan pengaruh dari pelat takaran yang belum distandardisasi; faktor metode dan manusia, dimana proses pengemasan sangat bergantung pada pekerja dan operator; serta faktor material. Tindakan perbaikan untuk meningkatkan nilai kapabilitas proses pengemasan pada mesin packing vertikal adalah memperkecil ukuran takaran dengan melapisi pelat takaran. Tindakan perbaikan yang dilakukan telah menaikan nilai Cp mie snack ‘Yakisoba’, ‘Migor’, dan ‘Mi Seblak’ sebesar 0,211;0,317;1,586. Namun, hasil observasi pada produk mie snack menunjukkan kurangnya keseragaman komposisi bahan pada produk akhir mie snack. Walaupun nilai Cp proses pengemasan meningkat akan tetapi nilai Cpk indeks kapabilitas proses pengemasan nilainya dibawah satu. Hal ini menunjukkan spesifikasi mesin packing vertikal yang digunakan PT XYZ tidak mampu memproduksi produk mie snack dengan spesifikasi yang ditetapkan perusahaan., Noodles snack is a processed food made from wheat flour using a frying process. Along with the high demand for snack noodle products from consumers, efforts are needed from PT. XYZ to increase the amount of production and reduce the number of broken products due to variations in product weight. The purpose of this study was to identify and analyze the factors causing variations in net weight of fried snack noodles at PT. XYZ and also calculate the value of Cp (Capability process) and Cpk (Index capability process) of the packaging process on vertical packing machine. This study uses the PDCA (Plan, Do, Check, Action) method with Ishikawa diagrams and control charts from SEVEN TOOLS. The results showed that the cause of the variation in product weight came from the engine factor, this was the influence of the measuring plate which had not been standardized; method and human factors, where the packaging process is highly dependent on workers and operators; and material factors. The corrective action to increase the value of the packaging process capability on vertical packing machines is to reduce the size of plate by coating the plate. The corrective action taken has increased the Cp value of ‘Yakisoba’ snack noodles, ‘Migor’ snack noodles, and ‘Mi Seblak’ snack noodles by 0.211; 0.317; 1.586. However, the results of observations on snack noodle products show a lack of uniformity in the composition of the ingredients in the final snack noodle product. Although the Cp value of the packaging process increases, the Cpk value of the packaging process capability index is below one. This shows that the specifications of the vertical packing machine used by PT XYZ are not able to produce snack noodle products
Keyword: PDCA cycles, Capability process, Index capability process, Vertical packing machines

Judul: Evaluation Cause of Chocolate Milk Powder Production Lower than Quantity Targets and Recommendation of Control Measure in PT.XYZ
Abstrak: Suatu industri makanan dan minuman dalam proses produksinya dapat mengalami masalah yang menyebabkan proses produksi menjadi tidak efisien. PT. XYZ diketahui dalam proses produksinya menggunakan Vacuum Belt Dryer dalam menghasilkan chocolate milk powder tidak efisien, karena hasil produksinya tidak mencapai target produksi. Penelitian ini bertujuan mengidentifikasi penyebab tidak tercapainya target kuantitas produksi chocolate milk powder menggunakan metode Fault Tree Analysis (FTA) dan Failure Mode Effect Analysis (FMEA) serta menyusun usulan tindakan pengendalian dan perbaikan untuk menghasilkan hasil produksi sesuai dengan target produksi. Hasil penelitian menunjukkan bahwa masalah yang sering terjadi pada proses produksi terdiri dari mesin VBD mengalami banyak unproductive time, parameter viskositas adonan tidak stabil, analisis viskositas adonan yang tidak aktual, serta yang menyebabkan kecepatan mesin berkurang dalam memproduksi produk. Analisis menggunakan FTA dan FMEA diketahui bahwa akar penyebab masalah adalah mekanisme pengeringan tidak efektif, waktu pengukuran viskositas adonan tidak tepat, tidak ada control untuk viskositas adonan yang masuk ke VBD, tidak ada uji homogenitas, operator tidak bekerja sesuai IK, belum ada siklus lifetime penggantian komponen mesin, pemasangan yang tidak efektif dengan kondisi produksi yang ada, keterampilan praktis teknisi dan operator, setting parameter produksi sudah tidak sesuai dengan kondisi aktual. Saran yang dapat diberikan berupa menetapkan metode dan periode pemeliharaan mesin yang tepat serta melakukan evaluasi terhadap berbagai setting parameter produksi. Penambahan spreader pada VBD, melakukan uji homogenitas adonan, dan menghitung volume adonan dapat dilakukan untuk menambah efisiensi mekanisme pengeringan adonan dengan mesin VBD. Sumber daya manusia yang terlibat juga harus ditingkatkan kemampuannya melalui pelatihan secara periodik terhadap penguasaan unit operasi dan intruksi kerja., A food and beverage industry in its production process can experience problems that cause inefficient production processes. PT. XYZ is run into a problem when producing chocolate milk powder, because the production results do not reach the production targets. This study aims to identify the causes of not achieving the quantity targets of chocolate milk powder production using the Fault Tree Analysis (FTA) and Failure Mode Effect Analysis (FMEA) methods and formulate proposed control and repair actions to produce chocolate milk powder in accordance with production targets. The results showed that the problems that often occur in the production process consisted of VBD machines experiencing a lot of unproductive time, unstable dough viscosity parameters, non-actual dough viscosity analysis, and those that caused the engine speed to decrease in producing the product. Analysis using FTA and FMEA shows that the root cause of the problem is an ineffective drying mechanism, incorrect dough viscosity measurement time, no control for dough viscosity that enters VBD, no homogeneity test, operators do not work according to IK, there is no replacement lifetime cycle. machine components, ineffective installation with existing production conditions, practical skills of technicians and operators, setting production parameters no longer in accordance with actual conditions. Advice can be given in the form of determining the appropriate method and period for machine maintenance as well as evaluating various production parameter settings. Adding a spreader to the VBD, performing a dough homogeneity test, and calculating the volume of dough can be done to increase the efficiency of the dough drying mechanism with
Keyword: chocolate milk powder, FTA, FMEA, reduce speed, vacuum belt dryer, viskositas, chocolate milk powder, FTA, FMEA, reduce speed, vacuum belt dryer, viskositas

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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