Problem description:

Consider the following process: Adam , Machine 1 do task 1, 2 do Brad and chloe Task 3 do David Task 4 do Adam performs tasks 1 and 2 with the same machine (machine 1). After running a setup on the machine, he performs task 1 on every unit in a batch. Then, he runs another setup on the same machine before performing task 2 on every unit in the batch. After that, either Brad or Chloe performs task 3 on all the units in the batch (i.e., the units are not split between the two of them). Finally, David does task 4. Tasks 3 and 4 do not require any setups. The setup time and production time per unit of each task is as follows: Task - 1 2 3 4 Time per unit (in mins) - 5 1 16 6 set up time (in min) - 20 30 0 0

Question :

Assume the batch size is 20 units. How long would it take to produce a batch starting with an empty system (where no setup has been done yet) under "one piece flow manufacturing"?