A toy factory is planning to make an additional item, which would be processed in 4 departments. The company is proposing to produce 600,000 units per year, working 250 days per year. The estimates of times made by an industrial engineer are in the table:                                  Departments Times   1   2   3    4 Average processing time (second/part) 8  13 10 50 Average maintenance, time/day (minutes) 20 30 20 15 Average daily setup, time (minutes) 20 15 30 20 Average bookkeeping, time/day (minutes) 10 8 12 5 Machine adjustment, time/day (minutes) 15 10 15 15 Defective items, (% of production) 5  6   4   4 The parts are produced within the departments in a sequential manner (from department 1 to 2 to 3 to 4).  2. Determine the number of machines needed in each department to meet the production goals.

At the beginning of each week, a machine is in one of four conditions: 1 = excellent; 2 = good; 3 = average; 4 = bad. The weekly revenue earned by a machine in state 1, 2, 3, or 4 is 100, 90, 50, or 10, respectively. After observing the condition of the machine at the beginning of the week, the company has the option, for a cost of 200, of instantaneously replacing the machine with an excellent machine. The quality of the machine deteriorates over time, as shown in the file P10 41.xlsx. Four maintenance policies are under consideration: Policy 1: Never replace a machine. Policy 2: Immediately replace a bad machine. Policy 3: Immediately replace a bad or average machine. Policy 4: Immediately replace a bad, average, or good machine. Simulate each of these policies for 50 weeks (using at least 250 iterations each) to determine the policy that maximizes expected weekly profit. Assume that the machine at the beginning of week 1 is excellent.