Usulan Peramalan dan Perancangan Sistem Persediaan Bahan Baku Tekstil Menggunakan Metode Time Series dan Min-Max (Studi Kasus: PT Kurios Utama Divisi Spinning 1)

Abstract

Abstrak

Persediaan merupakan aset penting bagi perusahaan karena berfungsi menunjang kelancaran proses produksi, meskipun target utama perusahaan adalah menjaga jumlah persediaan seminimal mungkin tanpa menghambat operasional. PT Kurios Utama, produsen tekstil di Jl. Raya Ungaran Bawen, Kabupaten Semarang, menghadapi permasalahan overstock bahan baku fiber, di mana pada bulan September terjadi kelebihan stok hingga 76,649 ton atau 422,45 bale, melebihi kapasitas gudang. Saat ini, perusahaan menerapkan sistem kontrak blanket order yang mewajibkan penetapan jumlah pembelian secara pasti dalam periode kontrak, sehingga perencanaan kebutuhan yang kurang akurat dapat memicu risiko overstock maupun kekurangan stok (stockout). Dalam penelitian ini, dilakukan peramalan dengan beberapa metode untuk mencari hasil dengan tingkat kesalahan terendah, di mana metode Double Moving Average T=5 dipilih karena menghasilkan MAPE sebesar 6,269%. Berdasarkan nilai error tersebut, ditentukan safety stock sebesar 60,491 ton atau 333,4 bale untuk mengantisipasi ketidakpastian permintaan. Selanjutnya, dilakukan pengendalian persediaan menggunakan metode Min-Max untuk memantau pergerakan stok, yang hasilnya mampu menekan Total Inventory Cost (TIC) sebesar Rp 7.251.750.000, sehingga pengelolaan persediaan menjadi lebih efisien dan terukur.

Kata Kunci: Time Series, Double Moving Average, Metode Min – Max, Overstock, Safety Stock

Abstract

(Proposal for Forecasting and Design of Textile Raw Material Inventory System Using Time Series and Min-Max Methods (Case Study: PT Kurios Utama Spinning Division 1)) Inventory is an important asset for a company as it supports the smooth running of the production process, even though the company's main goal is to keep inventory levels as low as possible without disrupting operations. PT Kurios Utama, a textile manufacturer located at Jl. Raya Ungaran Bawen, Semarang Regency, is currently facing an overstock issue of fiber raw materials, where in September the stock exceeded the warehouse capacity by 76.649 tons or 422.45 bales. The company currently applies a blanket order contract system, which requires a fixed quantity of purchases to be determined within the contract period. Inaccurate demand planning under this system increases the risk of either overstock or stockout. This research conducted demand forecasting using several methods to obtain the smallest possible error, with the Double Moving Average method (T=5) being selected for its accuracy, yielding a MAPE of 6.269%. Based on this error value, a safety stock of 60.491 tons or 333.4 bales was determined to anticipate demand fluctuations. Furthermore, inventory control was carried out using the Min-Max method to monitor stock movement, resulting in a reduction of the Total Inventory Cost (TIC) by Rp 7,251,750,000, making inventory management more efficient and well structured.

Keywords: Time Series, Double Moving Average, Min – Max Method, Overstock, Safety Stock