Mechoff case Job Shop design of production systems

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01. Design of Production Systems – Exercises 1 JOB SHOP EX. 1 In a small business it is going to design a new production system, organized in job shops. Two departments (M1, M2) will be installed and they will serve to produce 2 product types (A and B). The bill of process of the two products are as follows (Department, Cycle time on productive resource in [min/pcs]): A: (M1, 25) - (M2, 15) B: (M1, 15) - (M2, 25) The annual demand of the two products is given below: A: 12500 pieces B: 47500 pieces The production system will work 2 shifts of 8 hours per day, 300 days/year. Furthermore, some coefficients have been defined: the availability (A) of 0.9, the human coefficient (HC) of 0.9 and the trial rate (TR) of 0.85 for both departments. The scheduling efficiency is instead of 0.88. There are no production waste. In M1 department, setup lasts about 2 hours for each change of production; in M2 department, setup lasts instead 3 hours for each change of production. It is expected to produce medium batches of about 5000 pieces (regardless of the type of product).  The objective is to determine the number of machines and the rate of saturation for each department. A B Setup time Bill of process M1 [min/pc] 25 15 2 h = 120 min Bill of process M2 [min/pc] 15 25 3 h = 180 min Annual demand [pc] 12.500 47.500 Working hours: 2 shifts of 8 hours per day, 300 days/year A 0.9 Batches 5000 pieces HC 0.9 SE 0.88 TR 0.85 1.1.1 Solution - Total demand per year = 12.500 + 47.500 = 60.000 pc - Time for setup TS -> number of setups = 60.000/5.000 = 12 setup -> setup time M1 = 12 setup * 120 min/setup = 1440 min M2 = 12 setup * 180 min/setup = 2160 min - Production time PT -> M1 = 25 min/pc * 12.500 pc + 15 min/pc * 47.500 pc = 1.025.000 min -> M2 = 15 min/pc * 12.500 pc + 25 min/pc *…