Tugas Akhir Perencanaan dan Penentuan Inventory Untuk Meningkatkan Efisiensi dan Service Level Pada Perusahaan Industrial Distributor PT. XYZ
Diajukan guna melengkapi sebagian syarat dalam mencapai gelar Sarjana Strata Satu ( S1 )
Disusun Oleh Nama
: Ine Sintiya Devi
NIM
: 41614120116
Program Studi
: Teknik Industri
PROGRAM STUDI TEKNIK INDUSTRI FAKULTAS TEKNIK UNIVERSITAS MERCU BUANA JAKARTA 2016
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ABSTRAK Perusahaan PT. XYZ bergerak di bidang distributor, baik untuk industrial maupun retail.Penelitian berfokus pada salah satu produk industrial, yaitu cleaning. Tujuan penelitian ini untuk menentukan item apa saja yang dapat di stock dan jumlah quantity untuk mengurangi waktu pesan ke vendor agar dapat meminimalisir terjadinya stockout di salah satu store. Metode yang digunakan untuk penelitian ini yaitu ABC Analysis dan beberapa metode forecasting. ABC Analysis untuk menentukan item apa saja yang dapat distock dengan ketentuan transaksi penjualan dalam bulan per tahun ≥6 (klasifikasi item fast moving dan medium moving). Metode forecasting yang dipilih adalah Exponential Smoothing (α = 0,1) karena memilki nilai error forecast paling rendah. Itemyang menjadi stockakan dipasang replenishment automaticdengan Reorder point (ROP) dan Maximum Stock Level (MSL) untuk fullfillment stock di store. Hasil penelitian yang diperoleh ada 8 item yang akan menjadi stock di salah satu store , delapan item tersebut akan disetting replenishment automatic, lead time mempengaruhi quantity replenishment automatic, dan penggunaan metode dalam penelitian ini dapat meningkatkan efisiensi dan service level pada salah satu store PT. XYZ dibandingkan dengan perencanaan yang dijalankan secara manual karena hasil perhitungan sesuai dengan demand. Kata Kunci: ABC Analysis, Forecasting, Replenishment automatic, Fullfillment Stock, Lead Time, Stockout
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ABSTRACT Company PT. XYZ is a distributor company, specialized on industrial as well as retail. This research focuses on one of the industrial product, which is cleaning product. The objective of this research is to determine what are the items and the quantity to be stocked to reduce the lead time to vendor in order to minimize the occurrence of stock out in any stores. The method used on this research is ABC Analysis and forecasting method. ABC Analysis is used to determine what are the items to be stocked based on the sales in month per year ≥6 (classification fast moving item and medium moving). Forecasting method chosen is Exponential Smoothing (α = 0,1), because it has the least error forecast value. Items that are going to be stocked and will be fitted with Reorder point (ROP) and Maximum Stock Level (MSL) as a stock fulfillment on stores. Based on the research result obtained, there are 8 items that will become stock item in one of the store, these 8 items will be set automatic replenishment, lead time that influence quantity of automatic replenishment, and the method usage in this research can improve the efficiency and service level in one of PT. XYZ's store more than replenishment plan that run manually, since the calculation result is accordance to the demand.
Key Words : ABC Analysis, Forecasting, Replenishment automatic, Fulfillment Stock, Lead Time, Stockout
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KATA PENGANTAR Segala puji dan syukur penulis panjatkan atas kehadirat Allah SWT atas segala hidayah-Nya sehingga penulis dapat menyelesaikan tugas akhir sebagai salah satu syarat kelulusan dan meraih gelar S.T pada Program Studi Teknik Indutri. Tugas Akhir ini berjudul Perencanaan dan Penentuan Inventory Untuk Meningkatkan Efisiensi dan Service Level Pada Perusahaan Industrial Distributor PT. XYZ. Laporan tugas akhir ini tidak terlepas dari bimbingan dan arahan berbagai pihak. Penulis mengucapkan terima kasih kepada :
1. Orang tua dan kedua adik yang sangat penulis sayangi atas do’a dan dukungannya. 2. Bapak Resa Taruna Suhada, S.Si, MT selaku dosen pembimbing, yang telah memberikan bimbingan dan arahan kepada penulis dalam penulisan tugas akhir sehingga tugas akhir ini dapat diselesaikan. 3. Seluruh dosen dan staff TU Program Studi Teknik Industri. 4. PT. XYZ yang telah memberikan dukungan untuk penelitian ini. 5. Delga Wimas Irvano yang telah memberikan support yang luar biasa dan do'a. 6. Seluruh teman-teman Teknik Industri yang telah memberikan dukungan selama kuliah dan atas semua kerja sama, serta kebersamaan selama kuliah yang tidak akan pernah terlupakan. 7. Sahabat–sahabat SMA (Kepompong) atas dukungan doa dan semangatnya untuk penulis. 8. Semua pihak atas do'a dan dukungan yang tidak dapat disebutkan satu per satu. Penulis menyadari bahwa laporan penulisan tugas akhir ini masih jauh dari kesempurnaan. Baik dari segi pengetahuan, tata cara penulisan, maupun isinya karena
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keterbatasan penulis yang masih dalam tahap belajar. Oleh karena itu, kritik dan saran yang bersifat membangun diharapkan dapat memberi perbaikan di masa yang akan datang. Semoga laporan tugas akhir ini dapat bermanfaat bagi semua pihak. Akhir kata penulis mengucapkan terima kasih.
Jakarta, Juni 2016 Penulis,
Ine Sintiya Devi
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DAFTAR ISI
Lembar Pernyataan……..……………………………………………………………...………i Lembar Pengesahan…………..………………………………………………………ii Abstrak .........................................................................................................................iii Kata Pengantar .............................................................................................................. v Daftar Isi......................................................................................................................vii Daftar Gambar..............................................................................................................xi Daftar Tabel .................................................................................................................. x Lampiran ....................................................................................................................xiii Bab I .............................................................................................................................. 2 Pendahuluan .................................................................................................................. 2 1.1
Latar Belakang Masalah ................................................................................. 2
1.2
Perumusan Masalah........................................................................................ 4
1.3
Batasan Masalah............................................................................................. 5
1.4
Tujuan Penelitian............................................................................................ 5
1.5
Sistematika Penulisan..................................................................................... 5
Bab II............................................................................................................................. 7 Tinjauan Pustaka ........................................................................................................... 7 2.1
ABC Analysis .................................................................................................. 7
2.1.1
Definisi ABC Analysis ................................................................................…7
2.1.2
Tujuan ABC Analysis .....................................................................................7
2.1.3
Kelas Dalam ABC Analysis ...........................................................................8
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2.1.4
Tahapan dalam ABC Analysis .......................................................................9
2.2
Perencanaan Persediaan.................................................................................. 9
2.3
Peramalan Permintaan .................................................................................. 10
2.3.1
Definisi Peramalan (Forecasting) ............................................................. 11
2.3.2
Peranan dan Kegunaan Peramalan .............................................................13
2.3.3
Jenis-jenis Peramalan ...................................................................................14
2.3.4
Karakteristik Peramalan yang Baik ............................................................17
2.3.5
Jenis-jenis Pola Data ....................................................................................18
2.3.6
Teknik Peramalan .........................................................................................20
2.3.7
Ukuran Statistik Standar ..............................................................................25
2.3.8
Tracking Signal.............................................................................................27
2.3.9
Economic Order Quantity ...........................................................................28
2.3.10
Safety stock ....................................................................................................30
2.3.11
Reorder point (ROP) ....................................................................................31
2.3.12
Maximum Stock Level (MSL) ......................................................................32
Bab III ......................................................................................................................... 34 Metodologi Penelitian ................................................................................................. 34 3.1
Tipe Penelitian.............................................................................................. 34
3.2
Jenis Penelitian ............................................................................................. 35
3.3
Jenis Data ..................................................................................................... 35
3.4
Teknik Pengumpulan Data ........................................................................... 36
3.5
Teknik Pengolahan Data .............................................................................. 36
3.6
Langkah-langkah Penelitian ......................................................................... 37
Bab IV ......................................................................................................................... 39
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Pengumpulan Dan Pengolahan Data........................................................................... 39 4.1
Tinjauan Umum Perusahaan ........................................................................ 39
4.1.1
Sejarah Perusahaan .......................................................................................39
4.1.2
Visi dan Misi Perusahaan ............................................................................41
4.1.3
Struktur Organisasi.......................................................................................42
4.1.4
Lokasi Perusahaan ........................................................................................42
4.1.5
Gambaran Produk .........................................................................................43
4.2
Data Penelitian ............................................................................................. 43
4.2.1
Data Penjualan ..............................................................................................44
4.2.2
Data Quantity Customer ..............................................................................45
4.2.3
Lead Time Pembelian...................................................................................46
4.3
Pengolahan Data........................................................................................... 47
4.3.1
ABC Analysis........................................................................................ 48
4.3.2
Perhitungan Forecasting .............................................................................49
4.3.3
Perhitungan Rata – Rata Permintaan Per Item Dengan Metode Exponential
Smoothing (α = 0,1)......................................................................................................57 4.3.4
Perhitungan Quantity Replenishment automatic (Fullfillment Stock Secara
Otomatis) .......................................................................................................................64 Bab V .......................................................................................................................... 71 Analisa Hasil ............................................................................................................... 71 5.1
Analisa Hasil ABC Analysis ......................................................................... 71
5.2
Analisa Hasil Forecasting ............................................................................ 72
5.3
Analisa Simulasi Mengurangi Lead Time Pemesanan ke Vendor................ 72
Bab VI ......................................................................................................................... 78
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Kesimpulan Dan Saran................................................................................................ 78 6.1
Kesimpulan................................................................................................... 78
6.2
Saran ............................................................................................................. 79
Daftar Pustaka…………………………………………………………….………….80
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DAFTAR GAMBAR
Gambar 2. 1Kurva ABC Analysis............................................................................ 8 Gambar 2. 2 Pola Data Horizontal ........................................................................ 18 Gambar 2. 3 Pola Data Trend................................................................................ 19 Gambar 2. 4 Pola Data Musiman .......................................................................... 19 Gambar 2. 5 Pola Data Siklis ................................................................................ 20 Gambar 4. 1 Struktur Organisasi........................................................................... 42 Gambar 4. 2 Lokasi Perusahaan............................................................................ 42 Gambar 4. 3 Grafik Penjualan............................................................................... 44 Gambar 4. 4 Proses Pembelian ke Vendor ............................................................ 46 Gambar 4. 5 Grafik Forecast SMA ....................................................................... 51 Gambar 4. 6 Grafik Forecast ES (0,1)................................................................... 53 Gambar 4. 7 Grafik Forecast ES (0,3)................................................................... 55 Gambar 5. 1 Grafik Replenishment Auto ............................................................. 74
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DAFTAR TABEL
Tabel 2. 1 Review Referensi Jurnal ....................................................................... 33 Tabel 4. 1 Klasifikasi Item ................................................................................... 48 Tabel 4. 2 Hasil Forecast SMA ............................................................................. 50 Tabel 4. 3 Hasil forecast ES (0,1) ......................................................................... 52 Tabel 4. 4 Hasil forecast ES (0,3) ......................................................................... 54 Tabel 4. 5Hasil Forecast Error .............................................................................. 57 Tabel 4. 6 Hasil ES (0,1) Item A........................................................................... 57 Tabel 4. 7 Hasil ES (0,1) Item B ........................................................................... 58 Tabel 4. 8 Hasil ES (0,1) Item D........................................................................... 59 Tabel 4. 9 Hasil ES (0,1) Item F............................................................................ 60 Tabel 4. 10 Hasil ES (0,1) Item H........................................................................ 61 Tabel 4. 11 Hasil ES (0,1) Item L ......................................................................... 62 Tabel 4. 12 Hasil ES (0,1) Item O......................................................................... 63 Tabel 4. 13 Hasil ES (0,1) Item S ......................................................................... 63 Tabel 4. 14 Hasil ES (0,1) Semua Item................................................................. 65 Tabel 4. 15 Contoh Perhitungan SS ...................................................................... 67 Tabel 4. 16 Contoh Perhitungan ROP................................................................... 68 Tabel 4. 17 Contoh Perhitungan EOQ .................................................................. 69 Tabel 5. 1 Hasil Klasifikais Item........................................................................... 71 Tabel 5. 2 ReplenishmentItem A ........................................................................... 73 Tabel 5. 3 Qty ROP dan MSL............................................................................... 76
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LAMPIRAN
Lampiran 1. Data penjualan produk cleaning satu tahun terakhir ........................ 82 Lampiran 2. Data quantity customer per item....................................................... 83 Lampiran 3. Hasil penentuan klasifikasi item ....................................................... 84 Lampiran 4. Hasil Perhitungan Safety stock ......................................................... 85 Lampiran 5. Hasil Perhitungan Reorder point (ROP)........................................... 86 Lampiran 6. Hasil Perhitungan Economic Order Quantity (EOQ) ...................... 87 Lampiran 7. Hasil Perhitungan Maximum Stock Level (MSL) ............................ 88
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