Perancangan tata letak fasilitas pabrik dengan metode graph based construction dan differential evolution pada PT. Alvabetha Presisindo
P T. Alvabetha Presisindo yang berdiri sejak tahun 2015 bergerak dalam bidang manufaktur sebagai kontraktor utama industri komponen otomotif, khususnya penyedia peralatan penunjang produksi berupa Jigs, C/Fixture. Permasalahan yang terjadi pada PT. Alvabetha Presisindo adalah terjadinya cross traffic pada perpindahan antar departemen yang disebabkan peletakan departemen yang tidak ideal. Dengan terjadinya cross traffic sebanyak 35 titik yang menyebabkan biaya material handling menjadi tinggi dan perpindahan antar departemen tidak optimal. Perbaikan tata letak perlu dilakukan dengan tujuan mengurangi cross traffic yang terjadi pada lantai produksi. Penelitian memperbaiki tata letak lantai produksi dengan total 14 departemen, termasuk perbaikan Gudang bahan baku, Gudang bahan pembantu, dan penambahan area yaitu assembly storage area. Area assembly storage area merupakan departemen penghubung antara proses permesinan dengan proses perakitan. Part yang sudah melalui proses permesinan untuk proses milling ataupun CNC machine akan ditempatkan pada assembly storage area yang kemudian dipindahkan ke departemen welding area untuk dilakukan proses perakitan. Penambahan departemen tersebut diharapkan dapat mengurangi cross traffic yang terjadi dan meminimasi jarak. Perbaikan tata letak menggunakan metode graph based construction method (GBCM) dapat mengurangi cross traffic. Graph Based Construction Method dilakukan dengan cara mendekatkan jarak antar dua departemen yang memiliki hubungan kedekatan yang tinggi didalam From To Chart. From to chart memperhatikan besaran biaya material handling, yang ditentukan dari ongkos material handling per meter dikali jarak tempuh. Biaya material handling layout awal sebesar Rp 159.117. Tata letak usulan berdasarkan metode graph based construction method (GBCM) dioptimalkan menggunakan software Differential Evolution for Layout Planning (DFLP) yang melakukan pertukaran antar departemen dengan mempertimbangkan biaya material handling, Menyusun area fasilitas dengan menyesuaikan panjang dan lebar area yang dibutuhkan. Differential Evolution for Layout Planning (DFLP) akan melakukan pengurangan total jarak perpindahan material dan kebutuhan fasilitas dengan luas area yang berbeda. Dengan menggunakan metode tersebut diperoleh hasil sebanyak 3 alternatif layout. Layout pertama berdasarkan rancangan graph based construction, layout kedua dan hasil perhitungan differential evolution berdasarkan layout awal dan layout ketiga differential evolution berdasarkan hasil graph based construction. Tiga alternatif layout di evaluasi menggunakan Material Handling Evaluation sheet (MHES). Hasil MHES dibandingkan dengan alternatif lainnya. Perhitungan material handling evaluation sheet (MHES) layout alternatif pertama dengan graph based construction menghasilkan biaya sebesar Rp 65,715. Layout alternatif kedua berdasarkan hasil rancangan GBCM diperbaiki dengan differential evolution diperoleh biaya sebesar Rp 48,723 dan Layout alternatif ketiga dari layout awal diperbaiki dengan differential evolution diperoleh biaya sebesar Rp 52,623 Layout differential evolution berdasarkan metode graph based construction adalah alternatif layout terpilih berdasarkan hasil biaya perpindahan terendah dan Layout usulan yang terpilih telah mengurangi crosss traffic menjadi 12 titik
P T. Alvabetha Presisindo, which was established in 2015, is engaged in manufacturing as the main contractor for the automotive component industry, especially a provider of production support equipment in the form of Jigs, C/Fixtures. The problems that occur in PT. Alvabetha Presisindo is the occurrence of cross traffic in inter-departmental transfers caused by the placement of departments that are not ideal. With the occurrence of cross-traffic as many as 35 points which causes material handling costs to be high and transfers between departments are not optimal. Layout improvements need to be made with the aim of reducing cross traffic that occurs on the production floor. The research improves the layout of the production floor with a total of 14 departments, including repairs to the raw material warehouse, auxiliary materials warehouse, and the addition of an assembly storage area. The assembly storage area is a liaison department between the machining process and the assembly process. Parts that have gone through the machining process for the milling process or CNC machine will be placed in the assembly storage area which is then transferred to the welding area department for the assembly process. The addition of the department is expected to reduce cross traffic that occurs and minimize distances. Layout improvements using the graph based construction method (GBCM) can reduce cross traffic. Graph Based Construction Method is done by closing the distance between two departments that have a high close relationship in From To Chart. From to chart, pay attention to the amount of material handling costs, which are determined from the material handling costs per meter times the distance traveled. The initial layout material handling cost is Rp. 159,117. The proposed layout based on the graph based construction method (GBCM) is optimized using Differential Evolution for Layout Planning (DFLP) software which performs interdepartmental exchanges by considering material handling costs. Differential Evolution for Layout Planning (DFLP) will reduce the total distance of material transfer and the need for facilities with different areas. By using this method the results obtained as many as 3 alternative layouts. The first layout is based on the graph based construction design, the second layout and the calculation results of differential evolution are based on the initial layout and the third layout is differential evolution based on the graph based construction results. Three alternative layouts were evaluated using the Material Handling Evaluation sheet (MHES). MHES results were compared with other alternatives. The calculation of the first alternative material handling evaluation sheet (MHES) layout with graph based construction resulted in a cost of Rp. 65.715. The second alternative layout based on the results of the GBCM design was improved with a differential evolution, which obtained a cost of Rp. 48,723 and the third alternative layout from the initial layout was improved by a differential evolution, which obtained a cost of Rp. 52,623. The selected proposed layout has reduced cross traffic to 12 points