Biaya Bahan Baku dan Biaya Tenaga Kerja Dr Rilla Gantino, SE., Ak., MM PERTEMUAN 11 Dr Rilla Gantino, SE., Ak., MM Prodi Akuntansi- FEB

KEMAMPUAN AKHIR YANG DIHARAPKAN Mahasiswa dapat menghitung dan menginterpretasikan : penentuan dan pembebanan biaya bahan baku, masalah - masalah khusus yang berhubungan dengan biaya bahan baku (sisa bahan, produk rusak dan produk cacat). Mahasiswa dapat menghitung dan menginterpretasikan : penentuan dan pembebanan biaya tenaga kerja

Introduction Inventory in a company includes stock of raw materials, work-in-progress, finished & semi-finished products, spare components and by-products,etc Inventory control is an important feature of cost accounting system

Material control procedures Purchase Receipt Storage Stocktaking Issue

Material control procedures Establishing optimal stock levels is of vital importance of in controlling of stock Once the optimal stock levels are established, the store department is responsible for ensuring that optimal stock levels are maintained for each item of materials in stock. Normally, a bin card is used to record the quantity of materials in stock for each item

When items of materials have reached their re-order point, the storekeeper will make out a purchase requisition requesting the purchasing department to contact with appropriate supplier When the purchasing department receives the purchase requisition, the purchasing officer will examine the different sources of supply for the purpose of securing the highest quality materials at the lowest price

On the receipt of the goods, the stores department will inspect and compare the supply with the purchase order When the departmental foreman receives a production order, he will give a materials requisition to the storekeeper. On the receipt of requisition, the storekeeper checks for correctness and authorisation. If satisfactroy, the issue will be made and entered the details in bin cards. He then forwards the store requisition to accounts department

When the accounts department receives the stores requisition, it will price each of the items listed on it by appropriate pricing methods (e.g FIFO etc). Then, the amount of materials issued is charged to appropriate job or overhead account and the stock values are reduced

Pricing of the issues of material Pricing of materials may change from time to time. Materials are usually acquired by several deliveries at different prices Actual costs can then take on several different values Therefore, the materials pricing system adopted should be the simplest and the most effective one

Perolehan dan Penggunaan Bahan Baku Langkah-langkah pembelian dan penggunaan Bahan baku Routing dan BOM Anggaran Produksi Bukti permintaan pembelian Pesanan pembelian Laporan penerimaan Bukti permintaan bahan baku Kartu catatan bahan baku

Pembelian bahan baku Dilakukan oleh departemen pembelian Tugas departemen pembelian Formulir pembelian: Bukti permintaan pembelian Pesanan pembelian

Penerimaan Tugas departemen penerimaan Dokumen yang dibutuhkan: Laporan penerimaan

Persetujuan Faktur dan Pemrosesan Data Proses persetujuan faktur Biaya perolehan bahan baku Diskon Pembelian Beban angkut pembelian Biaya akuisisi yang dibebankan

Beban Angkut Pembelian (Freight In) Contoh: Harga beli : $ 600 Beban angkut : $ 48 Kuantitas : 25 item Berat : 1.700 pon. Cara membebankan: Jika barang yang dikeluarkan dari gudang untuk dikirim ke bagian produksi adalah 300 pon, maka yang dibebankan: Menambah biaya setiap item sebesar 8% Barang dalam proses (pengendali overhead pabrik) Beban Angkut Pembelian

Biaya Akuisisi yang Dibebankan

Penyimpanan dan Perhitungan Biaya Bahan Baku Bahan baku dan salinan laporan penerimaan dikirimkan ke gudang dari departemen penerimaan atau departemen pemeriksaan. Pengeluaran dan Perhitungan Bahan Baku Dokumen yang dibutuhkan

Model Kuantitatif Merencanakan kebutuhan bahan baku Faktor fundamental, yaitu jumlah dan waktu pembelian  melibatkan biaya penyimpanan dan biaya karena tidak menyimpan cukup persediaan. EOQ ( Economic Order Quantity) Jumlah persediaan yang dipesan pada suatu waktu yang meminimalkan biaya persediaan tahunan.

Economic Order Quantity (EOQ)

EOQ EOQ is the size of the order which contributes towards maintaining the stocks of material at the optimal level and at a minimum cost

The formula 2*O*Q EOQ = C Where EOQ = Economic Order Quantity O= order cost per order Q = Annual quantity required in units C =Carrying cost per unit per annum

Example The annual consumption of a part “X” is 5000 units. The procurement cost per order is $10 and the cost per unit is $0.5. The storage and carrying cost is 10% of the material unit cost. Required: Calculate the EOQ

Solution O= $10 Q= $5000, C= $0.5*10% 2 O Q EOQ = C 2 * 5000 *10 EOQ = = 1414 units

Cost $ Unit per order 120 Total cost Minimum cost 80 Carrying cost 40 Ordering cost EOQ=1414 units Unit per order 400 1200 2000

The graph shows the line representing ordering cost sloping downward, indicating lower cost when a large quantity is purchased and the line representing cost of carrying stock going upward, indicating a higher cost for a large quantity

Level setting

Level setting It is to determine the correct or most optimal stock level so as to avoid overstocking or understocking of materials These levels are known as the Maximum, Minimum and Re-order levels

Re-order level The level of stock of material at which a new order for the material should be placed The formula: Re-order level = (Maximum usage * Maximum lead time )

Re-order quantity Reorder quantity is the size of each order The formula: Reorder quantity = Maximum stock –(Reorder level – Minimum usage in minimum lead time)

Maximum level The maximum stock level is highest level of stock planned to be held Any amount above the maximum level will be considered as excessive stock The formula: Maximum level = re-order level + Re-order quantity(EOQ) –Minimum anticipated usage in Minimum lead

Minimum level/Safety stock The minimum level is that level of stock that provides a safety buffer in the event of increased demand or reduced receipt of stock caused by the lengthening of lead time The stock level should not be allowed to fall below the safety stock The formula: Minimum level= Re-order level – Average usage in average lead time

Units Maximum level 1500 Reorder level 1000 Minimum level 500 Weeks

Example

Average usage 100 units per week Minimum usage 70 units per week Maximum usage 140 units per week Lead time (the time between ordering and replenishment of goods) 3-5 weeks Ordering cost per order $180 Annual cost of carrying a unit in stock $5.2

Calculate: Economic Order Quantity (EOQ) Reorder level Reorder quantity Minimum level Maximum level

Economic Order Quantity (EOQ) 2 * $180 *5200 5.2 = 600 units

Reorder level Re-order level = (Maximum consumption * Maximum re-order period ) = 140 units *5 = 700 units

Minimum level Minimum level = Re-order level – Average usage in average lead time = 700 units – (100 units *4) = 300 units

Maximum level Maximum level = re-order level + EOQ –Minimum anticipated usage in Minimum lead = 700 units +600 units – (70 units *3) = 1090 units

Reorder quantity Reorder quantity = Maximum stock –(Reorder level – Minimum usage in minimum lead time) = 1090 units – (700 units – 70 units *3) = 600 units

Economic Order Quantity

EOQ (Lanjutan) Keterangan: EOQ = Economic Order Quantity RU = Jumlah kebutuhan per tahun CO = Biaya pemesanan (Cost per Order) CU = Biaya per unit (Cost per Unit) CC = Persentase biaya penyimpanan (Carrying Cost)

Contoh: Asumsikan kebutuhan per tahun sebesar 2.400 unit, biaya per unit $0.75, biaya pemesanan $20 per pesanan, dan persentase biaya penyimpanan adalah 20%. Hitung berapa EOQnya!

Contoh (Bila ada diskon pembelian) Asumsikan: penggunaan per tahun adalah 3600 unit dengan biaya per unit $1 tanpa diskon pembelian, biaya penyimpanan 20% dari rata-rata investasi dalam persediaan, serta biaya satu kali memesan sebesar $10.

Lanjutan: MAKA  Bila terdapat diskon pembelian sbb: Besar Pesanan 3600 unit 8% 1800 6 1200 5 900 720 4,5 600 4 450

Besar Pesanan Per Tahun Lanjutan Besar Pesanan Per Tahun 1 2 3 4 5 6 8 Biaya per unit $1 Diskon Pembelian 8% 6% 5% 4.5% 4% Harga per unit $0.92 $0.94 $0.95 $0.955 $0.96 Banyaknya pesanan dlm unit 3.600 1.800 1.200 900 720 600 450 Rata-rata persediaan dlm unit 360 300 225 Biaya rata2 persediaan $1.656 $846 $570 $427,50 $343,80 $288 $216 Biaya bahan baku /thn $3.312 $3.384 $3.420 $3.438 $3.456 Biaya Penyimpanan (20% dari rata2) 331,20 169,20 112 85,50 68,76 57,60 43,20 Biaya Pemesanan 10 20 30 40 50 60 80 Total Biaya/thn 3.653,2 3.573,2 3.564 3.545,5 3.556,76 3.573,6 3.579,2

Order Point (Re-order Point)  I + QD = LTQ + SSQ Keterangan: I = Saldo persediaan yang ada. QD = Jumlah yang akan diterima (sebelum I habis) dari pesanan yang sebelumnya sudah dilakukan, transfer bahan baku dan retur ke gudang. LTQ = Jumlah yang akan digunakan selama waktu tunggu, yang setara dengan waktu tunggu normal. SSQ = Jumlah persediaan pengaman

Contoh: Penggunaan Mingguan dari item persediaan tersebut: 175 unit Waktu tunggu normal : 4 minggu, max. 9 minggu. Persediaan awal : 2.800 unit

Solusi Titik pemesanan = 1.575 unit. Jumlah unit di persediaan awal 2.800 Penggunaan sampai di titik pemesanan kembali (1.225 / 175 penggunaan mingguan = 7 minggu) 1.225 Titik pemesanan kembali 1.575 Penggunaan selama waktu tunggu normal (700 / 175 penggunaan mingguan = 4 minggu) 700 Maksimum persediaan atau persediaan pengaman pada tanggal pesanan diterima, dengan asumsi waktu tunggu dan penggunaan normal 875 Jumlah pesanan yang diterima 2.090 Maksimum persediaan, dengan asumsi waktu tunggu dan penggunaan normal 2.965

Jika tingkat penggunaan dapat mencapai 210 unit, maka titik pemesanan : 1.890 unit. Jumlah unit di persediaan awal 2.800 Penggunaan sampai di titik pemesanan kembali (1.225 / 175 penggunaan mingguan = 7 minggu) 910 Titik pemesanan kembali 1.890 Penggunaan selama waktu tunggu normal (700 / 175 penggunaan mingguan = 4 minggu) 700 Maksimum persediaan atau persediaan pengaman pada tanggal pesanan diterima, dengan asumsi waktu tunggu dan penggunaan normal 1.190 Jumlah pesanan yang diterima 2.090 Maksimum persediaan, dengan asumsi waktu tunggu dan penggunaan normal 3.280