Perancangan Produk, Proses, Skedul dan Fasilitas session 3 Menghitung kebutuhan jumlah mesin/peralatan/stasiun kerja

Question before alternative facility plan What is to be produced ? How are the products to be produced? When are the products to be produced? How much of each product will be produced ? For how long will the products be produced ? Where are the products to be produced ?

Keterkaitan antara perancangan produk, proses, skedul dan fasilitas

Product designer specify what the end product is to be in terms of dimensions, material composition, perhaps, packaging. Process planner determines how the product will be produced. Production Planner specifies the production quantities and schedules the production equipment. Facilities Planner dependent on timely and accurate input from product, process and schedule designers to carry out his effectively.

Tool of product design QFD (Quality Function Deployment) is an organized planning approach to identify customer needs and to translate the needs to product characteristics, process design, and tollerances required. Benchmarking can also be used to identify what the competition is doing to satisfy the needs of your customer or to exceed the expectation of your customer.

Product Design Involves both the determination of which products are to be produced and the detailed design of individual product. Influenced by aesthetics, function, materials and manufacturing consideration. Marketing, purchasing, industrial engineering, manufacturing engieering, product engineering and quality control. In the final analysis, the product must be meet the need of the customer.

Sequence of product design Mengidentifikasikan kemauan pelanggan. Mempelajari ketentuan teknis dalam menghasilkan barang atau jasa. Hubungan antara keinginan pelanggan dengan ketentuan teknis. Membandingkan kinerja perusahaan dengan pesaing. Evaluasi pelanggan untuk membandingkan pendapat pelanggan tentang kualitas produk yang dihasilkan oleh perusahaan. Trade off untuk memberikan penilaian pengaruh antar aktivitas atau sarana yang satu dengan yang lainnya

QFD

Process Design Identifying required process Selecting the required process Sequencing the required process

Process Design Identifying Required Analysis The make or buy decision process Part list ( includes : part number, part name, number of parts per product) Selecting the required processes Route sheet data requirement Sequencing the required processes Assembly chart Operation process chart Precedence diagram

Schedule Design Marketing information Process requirement Scrap estimate Specifying Total Equipment Requirement

Scrap estimate Pk = percentage of scrap produced on the k operation Ok = desired output of non defective from operation k Ik = production input to operation k

Example 1 A product has a market estimate of 97,000 components and required three processing steps (turning, milling and drilling) having scrap estimates of P1= 0.04, P2 = 0.01 dan P3 = 0.03. Calculate I1, I2, , I3 !

Specifying Total Equipment Requirement F = number of machines required per shift S = standard time (minutes) per unit produced Q = number of units to be produced per shift E = actual performance H = amount of time (minute) available per machine R = reliability of machine

Example A machined part has a standard machinery time of 2.8 min per part on a milling machine. During an 8-hr shift 200 units are to be produced. Of the 480 min available for production, the milling machine will be operational 80% of the time. During the time the machine is operational, pasts are produced at a rate equal to 95% of the standard rate. How many milling machines are required ?

Contoh soal Part A is produced in machines 1 and 2. Part B is produced in machines 3 and 4. Part A and B are assembled in workstation 5 to create C. Assembly C is painted in process 6. Given the scrap percentage P1, … , P6 for each operation and the desired output O6 for C, determine an equation that can be used to calculate the required input I1 to machine 1.

Penentuan jumlah mesin teoritis PTLP Laboratory, 2007 Kapasitas mesin teroritis/minggu : Nilai jumlah yang diharapkan untuk operasi ke-n diperoleh dari nilai jumlah yang disiapkan pada operasi ke (n+1) dikalikan dengan jumlah pieces yang diperlukan.

Jumlah disiapkan Produksi efisiensi Jumlah mesin teoritis

Routhing Sheet _Soal Seorang manajer pabrik sedang merancang lantai pabriknya untuk menghadapi pesanan produk baru untuk tahun depan sebanyak 500.000 unit. Produk itu terbuat dari 2 komponen A, 1 komponen B dan 2 komponen C dengan data sebagai berikut :

Set up time/lot (menit) Komp No operasi No mesin Set up time/lot (menit) Run time/lot (menit) % scrap % reliability A 1 M-2 10 0.5 2 90 M-1 15 0.4 4 85 3 M-3 0.75 95 B 20 0.8 2.5 1.2 C 1.0 25 Produk R- 1 - 100

Adapun data penunjang lainnya adalah sebagai berikut : 1. Jumlah hari kerja per tahun : 300 hari 2. Jumlah jam kerja per hari 8 jam 3. Ukuran lot (A, B, C, Produk) (100, 200, 150, 1) unit 4. Efisiensi pabrik 90 + digit terakhir NIM anda

Anda diminta membantu manager tersebut dengan menghitung : Jumlah mesin yang diperlukan Jumlah kebutuhan bahan baku jika diketahui bahwa bahan baku berupa baja lembaran berukuran 120 cm x 200 cm x 3 cm yang setiap lembarnya dapat memproduksi 4 buah A, atau 5 buah B atau 10 buah C.

Case Study Sebagai seorang engineer anda diminta untuk merancang tata letak sebuah pabrik furniture berbahan dasar kayu rotan yang banyak dijumpai di pedalaman pelosok Indonesia yang produknya berupa kursi rotan, meja tamu, lemari, rak-rak hias bahkan kap lampu dan diharapkan akan mampu dieksport ke berbagai negara di AS dan Eropa. Untuk perancangan fasilitas pabrik tersebut dibutuhkan beberapa informasi antara lain informasi tentang : rancangan produk, rancangan proses dan rancangan skedul. Pertanyaan : Dapatkah anda menjelaskan kriteria-kriteria ketiga rancangan tersebut dan bagaimana kontribusinya terhadap rancangan fasilitas ?

TUGAS “Facilities Planning, 2nd James A. Tompkins dkk, Jhon Wiley and Sons, Inc, USA, 1996. 3.1, 3.9, 3.10, 3.11, 3.12, 3.13