Reference no: EM133447780

Problem 1

Patients arrive to a clinic every expo (2) minutes for examination. First a nurse registers them in Triangular (1, 2, 3) minutes. The nurse checks the doctors' queues and assigns the arriving patient to the shortest queue. Doctor Mansour and Doctor Hasan examine the arriving patients in Normal (5, 1) minutes. Next patients go to a pharmacy and take their medicines in Uniform (2, 4) minutes. Then the time in system is determined for the patients. Next the total cost is calculated based on the time the patient spends in the system and the medicine costs. It is known that each minute the patient spends in the system, it costs the clinic 0.250 KD and the expected medicine cost delivered to each patient is uniform (4, 8) KD. The following is the simulation model developed for this special case. Each module includes the related data in the text box above or below it.

Programs are also attached. Make one replication only and run it to answer the questions.

 

In the model above, fill out the empty spaces given above in the questions below and briefly explain in one sentence what the purpose is.

i) Arrive Time=

ii) In the decide node:
iii) Patient Cost=0.250*

Run the program and use the output to answer the following questions.

a) Is this a Terminating or Non-Terminating System and why?

b) What are the entities moving in the system (name)?

c) What are the resources in this system and what names?

d) How many patients are served by each doctor during the simulation period?

e) How many patients are left in the system when simulation was stopped?

f) What is the average number of patients in the system at any time?

g) What was the maximum number of patients in the system at any time?

h) What was the average waiting time for Doctor Mansour?

i) What was the average number of patients waiting for Doctor Hasan?

j) How many patients have been completed by Dr. Hasan?

k) What is meant by "VA Time"?

l) What is meant by "Wait Time"?

m) Why "half width" have been indicated as "insufficient" in the output?

n) Why do you think the Doctor utilizations are very high?

o) What was the average time each patient spent in the clinic?

p) Did the system start empty at the beginning of simulation replication, why?

q) What was the average time a patient spent waiting for the pharmacist?

r) What was the average total time the patient spent in the clinic by being served?

s) What was the longest duration any patient spent in the clinic?

t) Was it necessary to initialize statistics and why?

u) Was it necessary to initialize the system at the beginning and why?

v) Was it necessary to have warm-up period and why?

w) What outputs do you think could be considered as performance measures?

x) What could be considered as system parameters?

y) What could be considered as decision variables?

z) Since simulation is an experiment, what problem do you think these output results have? Can they be used as is? What should be done, if any?

Problem 2
The clinic manager has decided to improve the service by making the following changes: The queues for doctors are combined into a single queue. The patients are examined by any available doctor. Also, one more pharmacist is added to the system. The new clinic system is simulated using the modified model below. All data are the same except one more pharmacist is added. Initially make 1 replication and answer the following (a-c).

 

Answer the following questions by looking at the output on the next page.

a) What are the resources and their capacity in this model?

b) Indicate important measures that were improved in this model (Problem 2) compared to previous model (Problem 1).

Measures Improved Problem 1 Model Problem 2 Model

c) Indicate the measures that did not improve or became worse. Measures Not Improved Problem 1 Model Problem 2 Model

Problem 3
After analysis of the results, the manager decides to make 10 replications of the model given in Problem 2. Answer the following questions by using the output for replication 10, which is the average of all, given below.

a) What is the average number of patients leaving the system?

b) What is the 95% confidence interval on average patient waiting time in all queues?

c) What is the 95% confidence interval on the average time each patient spends in the clinic?

d) What is the standard deviation of the total time in system?

e) The manager wants to have more accurate results on patient time in the system. Therefore, he asks the simulation designer to provide a more accurate average time in system such that he is 95% of the time sure that the mean will be within ±1 minutes. How many simulation runs should be made to achieve such accuracy?

f) Suppose during that you would like to improve the system given by the model presented in Problem 2, which resource level (one of them) would you increase? Increase it by one unit and rerun the simulation to see the improvement achieved.