Problem 13 51 [PDF]

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Ex 13-51 Research Equipment Inc. (REC) is a small manufacturer of precision tools



used to construct research equipment for engineering departments at colleges and universities. It sells its two main products, REC-1 and REC-2, for $450 and $600, respectively. Due to increas ing demand and shortage of specialized labor, REC has found it increasingly difficult to meet the current weekly demand of 100 units of REC-1 and 60 units of REC-2. The following flow dia gram shows the manufacturing requirements for the two products and the three types of materials required. Material A is used in REC-1 only, Material C is used in REC-2 only, and Material B is used in both REC-1 and REC-2. The amount of weekly labor available for the four manufacturing operations follows: Receiving and testing materials: 6,000 minutes Machining (for Material A only): 10,000 minutes Assembly: 5,000 minutes Finishing: 10,000 minutes Flow Diagram



Assume that the labor for each operation is specialized and cannot be moved from one activity to another, that all operations except receiving and testing require a high level of skill, and that REC cannot increase the apacity on these operations in the short run. Required : What is the best production plan for REC? Why? Jawaban : Summary of Data for Research Equipment, Inc Demand (per week) Price Materials cost



$ $



REC-1 REC-2 100 60 450 $ 600 210 $ 300



Minutes Required for Each Product Per Unit Process 1: Receiving and testing materials 2: Machining 3: Assembly 4: Finishing



REC-1



REC-2 35 25 80 0 30 45 60 mklmmmmm



Total Minutes Available Per Week 6000 10000 5000 10000



Langkah 1 : Identifikasi Kendala Process 1: Receiving and testing materials Process 2: Machining Process 3: Assembly Process 4: Finishing



Minutes Required REC-1 REC-2 Total Minutes 3500 1500 5000 8000 0 8000 3000 2700 5700 6000 #VALUE! #VALUE!



Minutes Available Slack Minutes 6000 1000 10000 2000 5000 -700 10000



Langkah 2 Bagian 1 : Identifikasi Produk Paling Menguntungkan = REC-1 REC-1 REC-2 Price $ 450 $ 600 Material cost $ 210 $ 300 Throughput margin $ 240 $ 300 Constraint time (process 3) 30 45 Throughput margin per minutes $ 8,00 $ 6,67 Langkah 2 Bagian 2 : Identifikasi Komposisi Produk Paling Menguntungkan REC-1 REC-2 Permintaan 100 60 Komposisi produk yang optimal 100 44 Permintaan yang tidak bisa terpenuhi 16 Karena produk paling menguntungkan REC-1 maka seluruh permintaan untuk REC-1 dibuat terlebih dahulu. Kemudian untuk REC-2 dihitung dengan cara Pembuatan produk REC-1: 100 x 30 menit = 3000 menit Menit tersedia pada proses 3: 5000-3000= 2000 menit Sehingga sisanya untuk pembuatan REC-2 yaitu 2000 menit:45 menit = 44 unit (pembulatan) Dengan kondisi tenaga kerja untuk setiap operasi terspesialisasi dan tidak dapat dipindahkan serta tidak dapat meningkatkan kapasitas operasi dalam jangka pendek maka produksi terbaik yang paling menguntungkan ialah memproduksi 100 unit REC-1 dan 44 unit REC-2.