5. ( 20 points) A fabrication plant operates a single process technology with the following data (days): Layers 1 through 5 end with a photo step, while layer 6 ends at fab out. Photo is the bottleneck of the fab. On average, the total active WIP in the fab is 72 lots. The target cycle time is 12 days. (a) (7 points) Recommend target WIP levels by layer. (b) (6 points) Suppose there are two 12-hour shifts per day and suppose actual WIP distribution at the start of a shift is as follows: Compute one-shift IPQs and Schedule Scores for the photo steps. Assume line yield losses are negligible. (c) (7 points) Note the WIP anticipated to be available at each photo step during the upcoming shift displayed in the table immediately above. Suppose the fab has two photo machines. Machine #1 is expected to be 100% available this shift; machine 2 has a PM lasting 2.5 hours that is due this shift. Moreover, suppose each photo step has a process time equal to 0.4 hours per lot and that both machines are qualified to perform every photo step. At the end of the previous shift, machine \#1 had just finished running a lot of Layer 1 and machine \#2 had just finished running a lot of Layer 2. Prepare a good schedule for the photo machines. 5. ( 20 points) A fabrication plant operates a single process technology with the following data (days): Layers 1 through 5 end with a photo step, while layer 6 ends at fab out. Photo is the bottleneck of the fab. On average, the total active WIP in the fab is 72 lots. The target cycle time is 12 days. (a) (7 points) Recommend target WIP levels by layer. (b) (6 points) Suppose there are two 12-hour shifts per day and suppose actual WIP distribution at the start of a shift is as follows: Compute one-shift IPQs and Schedule Scores for the photo steps. Assume line yield losses are negligible. (c) (7 points) Note the WIP anticipated to be available at each photo step during the upcoming shift displayed in the table immediately above. Suppose the fab has two photo machines. Machine #1 is expected to be 100% available this shift; machine 2 has a PM lasting 2.5 hours that is due this shift. Moreover, suppose each photo step has a process time equal to 0.4 hours per lot and that both machines are qualified to perform every photo step. At the end of the previous shift, machine \#1 had just finished running a lot of Layer 1 and machine \#2 had just finished running a lot of Layer 2. Prepare a good schedule for the photo machines