Perancangan Sistem Kanban Pemasok Pada PT Semarang Autocomp Manufacturing Indonesia

Abstract

Sistem JIT memiliki hubungan yang sinkron dalam setiap mata rantainya. Untuk merealisasikannya, selain sistem kanban produksi dibutuhkan juga sistem kanban pemasok. Sistem kanban pemasok digunakan untuk menarik material dari pemasok yang mempunyai jarak geografis yang kecil ke perusahaan pemanufaktur. Sistem kanban pemasok dirancang dengan menerapkan manajemen rantai pasok yang mempertimbangkan rantai pasok antara pemasok dan pemanufaktur serta perlunya pemenuhan kebutuhan material (fill rate) sebesar 100% agar permintaan pelanggan dapat dipenuhi tepat kuantitas maupun waktu. Terdapat beberapa variabel yang perlu dianalisis lebih mendalam pada perancangan sistem kanban pemasok yaitu, ukuran kontainer/lot, frekuensi pengiriman, dan koefisien pengaman. Berdasarkan sistem pengendalian material pada objek penelitian, input sistem kanban pemasok yang dapat dianalisis lebih lanjut adalah frekuensi pengiriman. Frekuensi pengiriman ditentukan menggunakan model SSMD (single-setup-multiple-deliveries) atau JIT lot-splitting untuk manajemen rantai pasok yang dikembangkan untuk meminimasi biaya persediaan agregat antara pemasok dan pemanufaktur. Ukuran performansi model sistem kanban pemasok yaitu, volume persediaan SAMI, terjadinya shortage, fluktuasi jumlah pesanan, inventory days of supply, dan biaya persediaan agregat. Hasil perancangan sistem kanban pemasok pada SAMI dengan PASI-AW sebagai pemasok menunjukkan bahwa sistem kanban pemasok dapat mengurangi volume persediaan hingga 36,61%, fluktuasi pesanan berkurang dari 48% menjadi 29%, inventory days of supply berkurang dari 7 hari menjadi 4 hari, dan menghemat biaya agregat hingga 34,82%. Walaupun perancangan sistem mengestimasikan akan terjadi shortage, hal tersebut dapat diantisipasi sehingga fill rate mencapai 100%. JIT system has a syncron relation among its supply chains. To realize a syncron JIT system, besides implementing kanban system on production line, kanban system on inventory control is also needed. Kanban system on inventory control called supllier kanban, which is used to withdraw material from supplier -who has a short geographic distance- to manufacturer. Supplier Kanban System was design by considering supply chain management between supplier and the need of fulfillling 100% fill rate of material requirement. There are some variables in designing kanban supplier system which can be analyzed for further researc, such as lot/container size, number of times of conveyance or delivery frequency, safety coefficient, and order frequency which used to see the impact on supplier. Based on inventory control system on the research object, the variable which might undergo further analysis was delivery frequency. Delivery frequency was determined using SSMD (single-setup-multiple-deliveries) model, known as JIT lot-splitting model for supply chain management that was built to minimize total inventory cost aggregate between supplier and manufacturer. Performance measurements on supplier kanban system model were SAMI’s inventory volume, shortage which may occur, order quantity fluctuation, inventory days of supply, and total cost inventory aggregate. The results of supplier kanban system design on SAMI with PASI-AW as supplier showed the decreasing of inventory volume up to 36,61%,, the decreasing of quantity order fluctuation from 48% to 29 %, the decreasing of inventory days of supply from 7 days to 4 days, and the decreasing of total inventory cost aggregate up to 34,82%. Eventhough shortages were estimated occur on the system, this could be anticipated so that the system reached 100% fill rate.