Consider the following batch process and assume the demand rate is 15 units per hour. After task 1 is completed, the production unit is divided into two parts (top and bottom). Tasks 2 and 7 are done on the top of the unit and tasks 3, 4, 5 and 6 are done on the bottom of the unit. Tasks 3, 5 and 6 are currently done by the same robot, which is operated by one worker (Fiona for task 3, Erin for tasks 5 and 6). Preparing the robot for tasks 3 and 5 takes (virtually) no time. However, setting it up for task 6 takes 10 minutes before every batch. Task 4 consists of having the bottom part of the flow units cool down on a cooling rack. The cooling rack can hold up to 20 units at the same time. Task 7 can be done either by Bob or by Chloe, who each have their own machine. Task 8, which consists of reassembling the top and bottom parts of the units, is currently done by Adam using a screwdriver. Task 9 is done with machine 3 operated jointly by Adam and George. The setup time and the actual production for task 9 require the presence of both workers. Machine 3 can only process one unit at a time. All setups are required between two batches. The production is currently done in batches of 10 units. Here is the process flow diagram of the process
:https://d2vlcm61l7u1fs.cloudfront.net/media%2F03d%2F03d133ff-f3ce-4d41-a240-84e61bdaad37%2FphpKNO4GJ.png
(a) What is process capacity and what is (are) the bottleneck(s) of the process? What is the cycle time? Is the process supply‐ or demand‐constrained? Show all your work.
(b) The manager of the process wants to increase profits (i.e., revenues minus costs). What do you think of the following options:
(i) Increasing the batch size to 20 units.
(ii) Buy a new robot to replace the existing one (and throw away the old one). The new robot can do task 3 in 1 minute per unit instead of 2 minutes (but the time it takes to do tasks 5 and 6 is as before).
(iii) Lay off Fiona and have Adam replace her. So in the new process Adam would do tasks 1, 3, 8 and 9.
(iv) Reorganize the process so tasks 2 and 7 can be done at the same time on the same flow unit.
(v) Have Fiona work with Dorothee on task 2 so task 2 would only take 3 minute per unit instead of 6. So in the new process Fiona would be doing tasks 2 and 3 and Dorothee would still be doing task 2.
(vi) Advertise to increase the demand rate to 20 units per hour.
(vii) Increase the selling price of the units. This will decrease the demand rate to 10 units per hour.