operation management HW1
1. A manufacturer's average work-in-process inventory for a certain part is 1,000 units. The workstation produces this part at the rate of 200 units per day. What is the average time a unit spends at this workstation?
2. The Wilcox Student Health Center has just implemented a new computer system and service process to \improve e±ciency." As pharmacy manager, you are con- cerned about waiting time and its potential impact on college students who \get no respect." All prescriptions (Rxs) go through the following process:
Drop-o® ! Fill Rx ! Pick-up ! Cashier
Assume that students arrive to drop-o® Rxs at a steady rate of 2 Rxs per minute, with an average of one Rx per student. The average number of students in process
(those who are waiting and those who are being served) at each station is:
Drop-o® - 5 students
Pick-up - 3 students
Pay cashier - 6 students
On average, the Fill Rx station has 40 Rxs in process and waiting. Because of this perceived long wait, 95% of the students decide to come back later for pick-up.
They come back an average of 3 hours later. If the students choose to stay, their name is called as soon as the Rx is ¯lled and they then enter the pick-up line.
Assume that the system is operating at a steady state.
a) Draw a °ow diagram for the entire process. Include °ow paths for students
(solid lines) and prescriptions (dashed lines).
b) What is the average time in the pharmacy for those students who stay to pick-up their Rxs?
c) What is the average time in the pharmacy for those students who pick-up 3 hours later (i.e., they go home after dropping the Rx o®)?
d) What is the average time that a student spends in the pharmacy?
3. A hospital emergency room (ER) is currently organized so that all patients register through an initial check-in process. At his or her turn, each patient is seen by a doctor and then exits the process, either with a prescription or with admission to the hospital. Currently, 50 people per hour
2. The Wilcox Student Health Center has just implemented a new computer system and service process to \improve e±ciency." As pharmacy manager, you are con- cerned about waiting time and its potential impact on college students who \get no respect." All prescriptions (Rxs) go through the following process:
Drop-o® ! Fill Rx ! Pick-up ! Cashier
Assume that students arrive to drop-o® Rxs at a steady rate of 2 Rxs per minute, with an average of one Rx per student. The average number of students in process
(those who are waiting and those who are being served) at each station is:
Drop-o® - 5 students
Pick-up - 3 students
Pay cashier - 6 students
On average, the Fill Rx station has 40 Rxs in process and waiting. Because of this perceived long wait, 95% of the students decide to come back later for pick-up.
They come back an average of 3 hours later. If the students choose to stay, their name is called as soon as the Rx is ¯lled and they then enter the pick-up line.
Assume that the system is operating at a steady state.
a) Draw a °ow diagram for the entire process. Include °ow paths for students
(solid lines) and prescriptions (dashed lines).
b) What is the average time in the pharmacy for those students who stay to pick-up their Rxs?
c) What is the average time in the pharmacy for those students who pick-up 3 hours later (i.e., they go home after dropping the Rx o®)?
d) What is the average time that a student spends in the pharmacy?
3. A hospital emergency room (ER) is currently organized so that all patients register through an initial check-in process. At his or her turn, each patient is seen by a doctor and then exits the process, either with a prescription or with admission to the hospital. Currently, 50 people per hour