## what method of generating random variable is correct in this problem?

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Ryan
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Joined: Wed Jun 19, 2019 11:41 am
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### what method of generating random variable is correct in this problem?

hi
I have made a model in which a surgeon performs surgeries on multiple patients. The surgeon is capable of performing 2 different types of surgeries (type A and type B). type A surgery is more desirable but at the same time, it requires more skills from the surgeon compared to type B surgery.
It is assumed that the surgeon of our model has a fixed level of skills but the required skill to perform type A surgery on different patients varies depending on their demographic and clinical characteristics.
In order to simulate the different level of difficulty of performing type A surgery in different patients, a random number is assigned to each patient showing the level of skills required from the surgeon to enable him to perform type A surgery on that patient.
clearly, if the skill of the surgeon is equal to or more than the skill required to perform surgery on a patient (random number), type A surgery will be performed otherwise, type B is performed.

I have used “Pink Noise” with the following formulation to generate random number in this model, is this way of generating random number correct in this problem? of not, what is the right way of generating random numbers in this problem.

noise seed = 1
unit = Dmnl

mean = 0
unit = skill

standard deviation = 1
unit = skill

time step = 0.015625
unit = year

correlation time = 2
unit = year

white noise = RANDOM NORMAL( -1e+06, 1e+06, mean, standard deviation*((2-TIME STEP/correlation time)/(TIME STEP/correlation time))^0.5 , noise seed)
Unit = skill

change in pink noise = (white noise-pink noise)/correlation time
unit = skills/Year

pink noise = INTEG (change in pink noise)
initial value = RANDOM NORMAL(-100, 100, mean, standard deviation, noise seed)
unit = skill

Ryan
Junior Member
Posts: 6
Joined: Wed Jun 19, 2019 11:41 am
Vensim version: PLE