Due to a product upgrade, two new operations are need for the new version of the part mentioned in Practice Problem 1. Operation 3 is a high-precision drilling operation. Machine 3 has a mean time to fail of 10 hours and a mean time to repair of 45 minutes. Machine 4 paints the part pink1. Its mean time to fail is 100 hours and its mean time to repair is 6 hours. The operation times of Machines 3 and 4 are 2 minutes.

When the line is rebuilt there may be buffers between the machines. As the manufacturing systems engineer, your job is to decide whether buffers are needed. (It will also be to decide what size the buffers should be, but that issue is treated in the second part of this course.)

Part 1

What is the maximum production rate that the line can achieve with-out buffers in parts per minute?

Part 2

What is the maximum production rate that the line can achieve with buffers in parts per minute?

Part 3

At what rate does material accumulate in the line if it has infinite buffers in terms of parts per minute?
 

Machine e 0.9346 (7)(60) 6000 2 0.9231 300 (60)G0) 3 0.9302 45 (10G0) 4 0.9434 (6)(60) (100)(60) Table 1: Summary of machine parameters