MGT 3121 HW

Patients are arriving at a clinic at a rate of two per minute. Each patient's visit consists of four steps: check in, record vital signs, receive treatment, and check out. A receptionist takes 1 minute to check a patient in. A nurse takes 2 minutes to record the patient's vital sign. A doctor spends 10 minutes with a patient. A staff member takes 3 minutes to check a patient out. What is the utilization of the staff member checking out patients?

Utilization of checkout = flow rate/capacity of process (checkout) flow rate = 3 min capacity of process = bottleneck = (doctor) 10 min utilization = 3/10 = .30 = 30%

For the project network described in Question 8, the critical path and project duration for the process is: A-B-D-F and 16 A-C-E-F and 15 A-C-D-F and 13 A-B-C-D-E-F and 26

A-B-D-F having total project duration = 16 Critical path is one which is having the highest project duration. (A-B-C-D-E-F and 26 is not possible bc B does not go to C)

Consider a simple process where work flows from Activity A to Activity B to Activity C to Activity D. Activity A takes 3 minutes and is performed by Aaron. Activity B takes 5 minutes and is performed by Aaron and Betty together. Activity C takes 4 minutes and is performed by Betty and David together. Activity D is performed by David and takes 3 minutes. What is the bottleneck of the process?

Calculate the capacity of each operation: A = 1/3 = 0.33 per hr B = 2/5 = 0.4 per hr C = 2/4 = 0.5 per hr D = 1/3 = 0.33 per hr Activity A & D are the bottlenecks as they have the minimum capacity. Activity A & B include Betty - Betty makes an activity longer to complete therefore - BETTY is the BOTTLENECK.

Guests are arriving at a party at a rate of 12 per minute. Each guest will be checked in, served a drink, and accompanied to his/her table by one receptionist, one bartender, and one usher respectively. Both the receptionist and usher can serve 10 guests per minute, whereas the bartender takes 5 minutes to serve one guest. Which resource is the bottleneck and what is the process capacity in guests per minute?

Capacity = 1/Process time. Capacity for both the receptionist and usher = 10 guests per minute. Capacity of the bartender is 1/5 = 0.2 guest per minute. The bottleneck is the bartender because it is the resource with the lowest capacity. The lowest capacity also defines the process capacity, which is 0.2 guest per minute. Bartender, 0.2

Consider the following project network with activity duration specified on each node. What are the Earliest Start Time (EST) and Early Competition Times (ECT) for activity D?

EST = Max (ECT of the Predecessors) ECT = EST + Duration EST D = Max (ECT B, ECT C) ECT D = EST D + Duration of D EST B = ECT A =​ 0+5 = 5 ECT B = EST B + Duration of B = 5+7=12 EST C = ECT A =​ 0+5 = 5​ ECT C = EST C + Duration of C = 5+4=9 EST D = Max(12, 9) = 12 ECT D = EST D + Duration of D = 12+3 = 15 = 12 and 15

Students are going through a three-step process to obtain their ID cards. Each student will first visit the only registration desk before going to one of three cashiers to pay a fee for the card. After that, he/she will visit one of the four ID processing stations to have his/her picture taken and the ID card printed. Registration takes 2 minutes. Visits to the cashier and ID processing station take 10 and 20 minutes, respectively. If the bottleneck resource has the utilization of 0.75 (i.e. it is 75% busy), what is the flow rate through the process?

Find flow rate. Effective flow time of registration desk = 2 minutes Effective flow time for payment of fees to cashiers = 10/3 minutes (since there are 3 cashiers working simultaneously) Effective flow time at ID processing station = 20/4 = 5 min (since there are 4 ID processing stations working simultaneously) ID processing station = highest flow time = bottleneck = 5 min theoretical flow rate through the process per hour = 60 min/ flow time = 60/5 = 12 students per hour It is however given that bottleneck resource and hence effectively the process is 75% busy. Therefore effective flow rate through the process = 75% of 12 students = 9 students per hour

An activity on the project network has a slack time of 2 days. Which of the following is NOT true? - Increasing the activity time by 2 days would make this activity critical for the project. - Increasing the activity time by 2 days would decrease its slack time by 2 days. - Increasing the activity time by 2 days would increase its slack time by 2 days. - Increasing the activity time by more than 2 days would increase the project duration.

Increasing the activity time by more than 2 days would increase the project duration. OR Increasing the activity time by 2 days would increase its slack time by 2 days.

Job candidates are leaving an office every 50 minutes. Each candidate goes through three activities during the office visit: verification, written test, and interview. Verification takes 1 minute, the written test takes 40 minutes, and the interview takes 10 minutes. Assume there is only one resource dedicated to each activity. What is the process capacity in candidates per hour?

Process Capacity = 60 (min/hr) / (bottleneck = 40 min) = 60/40 = 1.5 - candidates per hour*** --- Job candidates are leaving an office every 50 minutes. Job Process Capacity = (=60 min*(1 candidate/50 min)) = 1.2 candidates per hour Since, none of the individual process have capacity lower than 1.2, the process does not have any bottleneck. But if the number of candidates increases, the written test will become bottleneck capacity.

One employee is in charge of the following activities at a drive-through of a bank: Greet customer - 2 seconds Take order - 3 seconds Process order - 2 minutes Print receipt - 10 seconds What is the capacity (in customers per hour) of the employee?

Processing Time = 2 sec + 3 sec + 2 min + 10 sec = 135 sec Process Capacity = 1/135 * 60 (sec/min) * 60 (min/hr) = 26.67

A dentist's office has three types of workers: dentists, nurses, and receptionists. On average a dentist sees each patient for 45 minutes, the nurses spend an hour with each patient, and the receptionist spends 10 minutes with each patient. Suppose 6 patients visit the dentist's office per hour. What is the smallest number of dentists, nurses and receptionist required to serve demand?

Receptionist spends 10 minutes with each a patient. In 1 hour (60 min) a receptionist will be able to attend to 60/10 = 6 patients. This is also the number of patients visiting the dentist's office in an hour. - only 1 receptionist required Nurse spends an hour with each patient. Total hours requirement for 6 patients = 6*1 = 6 hours. - # of nurses required = 6 hours in total/1 hour per patient = 6 Dentist sees a patient for 45 minutes. In an hour a dentist is able to see a full patient and allot the balance time of 15 minutes (60 minutes - 45 minutes) to the next patient. Total # of patients served in an hour = 1+(15/45) = 1.33. As there are 6 patients: # of dentists = 6/1.33 = 4.5. This will be rounded to the next whole number i.e. 5. = 5 dentists are required. - 5 dentists, 6 nurses and 1 receptionist